Devices, systems, and methods for controlling active drive systems

ABSTRACT

The present application is related to devices, systems, and methods for controlling active drive systems. In one embodiment, the drive system may include a first surface and a second surface for engaging an elongate member. The first and second surfaces may be attached to a drive mechanism to move the elongate member. The first surface may be slidable relative to the drive mechanism and may have a clearance between the drive mechanism and an end of the first surface during movement of the elongate member in a non-slip condition. A sensor may be associated with the first surface and may be configured to detect movement of the first surface in a slip condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 61/982,021, titled “Variable Stroke for Drive Devices”, filedon Apr. 21, 2014; U.S. provisional patent application Ser. No.61/984,354, titled “Slip Detection by Differential Pad Strain”, filedApr. 25, 2014; U.S. provisional patent application Ser. No. 62/016,334,titled “Multi-Durometer Pad System”, filed on Jun. 24, 2014; U.S.provisional patent application Ser. No. 62/031,925, titled “SlipDetection by Passive Pad Movement”, filed Aug. 1, 2014; U.S. provisionalpatent application Ser. No. 62/042,451, titled “Control Mechanisms forActive Drive with a Slip Detection Capability”, filed Aug. 27, 2014, allof which are herein incorporated by reference in their entirety.

This application is related to U.S. provisional patent application Ser.No. 61/922,984, titled “Catheter Assembly for Slip and BucklingDetection”, filed Jan. 2, 2014; U.S. provisional patent application Ser.No. 61/925,746, titled “A method to use electrical current profiles tosynchronize and align motors”, filed on Jan. 10, 2014, all of which areherein incorporated by reference in their entirety.

This application is related to U.S. patent application Ser. No.13/838,777, titled “Active Drive Mechanism with Finite Range of Motion”,filed on Mar. 15, 2013; U.S. patent application Ser. No. 13/835,136,titled “Active Drive Mechanism for Simultaneous Rotation andTranslation”, filed Mar. 15, 2013; U.S. patent application Ser. No.13/803,535, titled “Active Drives for Robotic Catheter Manipulators”,filed Mar. 14, 2015, all of which are herein incorporated by referencein their entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety, as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates generally to the robotic medical devices field,and more specifically to new and useful devices, systems, and methodsfor controlling active drive systems.

BACKGROUND

For medical procedures, minimally invasive procedures are preferred overconventional techniques wherein the patient's body cavity is open topermit the surgeon's hands access to internal organs. Thus, there is aneed for a highly controllable yet minimally sized system to facilitateimaging, diagnosis, and treatment of tissues which may lie deep within apatient, and which may be accessed via naturally-occurring pathways,such as blood vessels, other lumens, via surgically-created wounds ofminimized size, or combinations thereof.

Currently known minimally invasive procedures for the treatment ofcardiac, vascular, and other disease conditions use manually orrobotically actuated instruments, which may be inserted transcutaneouslyinto body spaces such as the thorax or peritoneum, transcutaneously orpercutaneously into lumens such as the blood vessels, through naturalorifices and/or lumens such as the mouth and/or upper gastrointestinaltract, etc. Manually and robotically-navigated interventional systemsand devices, such as steerable catheters, are well suited for performinga variety of minimally invasive procedures. Manually-navigated cathetersgenerally have one or more handles extending from their proximal endwith which the operator may steer the pertinent instrument.Robotically-navigated catheters may have a proximal interface configuredto interface with a catheter driver comprising, for example, one or moremotors configured to induce navigation of the catheter in response tocomputer-based automation commands input by the operator at a masterinput device in the form of a work station.

In the field of electrophysiology, robotic catheter navigation systems,such as the Sensei® Robotic Catheter System (manufactured by HansenMedical, Inc.), have helped clinicians gain more catheter control thataccurately translates the clinician's hand motions at the workstation tothe catheter inside the patient's heart, reduce overall procedures(which can last up to four hours), and reduce radiation exposure due tofluoroscopic imaging necessary to observe the catheter relative to thepatient anatomy, and in the case of electrophysiology, within therelevant chamber in the heart. The Sensei® Robotic Catheter Systememploys a steerable outer catheter and a steerable innerelectrophysiology (EP) catheter, which can be manually introduced intothe patient's heart in a conventional manner. The outer and innercatheters are arranged in an “over the wire” telescoping arrangementthat work together to advance through the tortuous anatomy of thepatient. The outer catheter, often referred to as a guiding sheath,provides a steerable pathway for the inner catheter. Proximal adapterson the outer guide sheath and inner EP catheter can then be connected tothe catheter driver, after which the distal ends of the outer sheath andinner EP catheter can be robotically manipulated in the heart chamberwithin six degrees of freedom (axial, roll, and pitch for each) viaoperation of the Sensei® Robotic Catheter System.

While the Sensei® Robotic Catheter System is quite useful in performingrobotic manipulations at the operational site of the patient, it isdesirable to employ robotic catheter systems capable of allowing aphysician to access various target sites within the human vascularsystem. In contrast to the Sensei® Robotic Catheter System, which may beused in conjunction with sheaths and catheters that are both axially andlaterally rigid, robotic catheter systems designed to facilitate accessto the desired target sites in the human vascular system requiresimultaneous articulation of the distal tip with continued insertion orretraction of an outer guide sheath and an inner catheter. As such, theouter guide sheath and inner catheter should be laterally flexible, butaxially rigid to resist the high axial loads being applied to articulatethe outer guide sheath or inner catheter, in order to track through thetortuous anatomy of the patient. In this scenario, the inner catheter,sometimes called the leader catheter extends beyond the outer sheath andis used to control and bend a guidewire that runs all the way throughthe leader catheter in an over-the-wire configuration. The innercatheter also works in conjunction with the outer guide sheath andguidewire in a telescoping motion to inchworm the catheter systemthrough the tortuous anatomy. Once the guidewire has been positionedbeyond the target anatomical location, the leader catheter is usuallyremoved so that a therapeutic device can be passed through the steerablesheath and manually operated.

As shown in FIG. 1, robotic catheter systems typically employ a roboticinstrument driver 1 to provide robotic insertion and refractionactuation, as well as robotic steering actuation, to a telescopingassembly of elongate flexible instruments. The instrument driver 1comprises a housing 2 that contains motors (not shown) for providing therobotic actuators to the telescoping assembly, which may include anouter steerable guide sheath 3, an inner steerable leader catheter 4disposed within the sheath catheter, and a conventional guidewire 5disposed within the leader catheter 4.

The robotic instrument driver 1 may robotically insert/retract theleader catheter 4 relative to the sheath catheter 3. To this end, theproximal ends of the guide sheath 3 and leader catheter 4 aremechanically interfaced to the instrument driver 1 in such a manner thatthey may be axially translated relative to each other via operation ofthe motors, thereby effecting insertion or retraction movements of therespective guide sheath 3 and leader catheter 4. In the illustratedembodiment, the guide sheath 3 and leader catheter 4 respectivelyinclude proximal steering adapters 6, 7 (“splayers”) mounted toassociated mounting plates 8, 9 on a top portion of the instrumentdriver 1. In the illustrated embodiment, each of the proximal adapters6, 7 can be actuated via motors (not shown) within the housing 2 of theinstrument driver 1 to deflect or articulate the distal ends of therespective guide sheath 3 and leader catheter 4 in any direction.

Unlike the steerable guide sheath 3 and leader catheter 4, the distalends of which can be robotically articulated via the instrument driver1, the guidewire 5 is conventional, and thus, its distal end is notcapable of being robotically articulated. Instead, as with mostconventional guidewires, the guidewire 5 may be manipulated byinserting, retracting, or rolling or by simultaneously rolling whileaxially displacing the guidewire. In a non-robotic environment, suchmanipulations can be accomplished by pinching the proximal end of theguidewire between the forefinger and thumb of the physician and movingthe forefinger relative to the thumb while axially displacing theguidewire.

In order to navigate the guide sheath 3 and leader catheter 4 throughthe tortuous anatomy of a patient, it is desirable that these componentsbe laterally flexible. However, the flexibility of the leader catheter 4may create issues when performing the robotic insertion actuation. Inparticular, due to the flexibility of the leader catheter 4 and therelatively long distance between the mounting plate 9 and the point atwhich the leader catheter 4 is contained within the guide sheath 3, theleader catheter 4 may buckle, thereby preventing it, or at leasthindering it, from axially translating within the guide sheath 3.Although “passive” anti-buckling devices may be used to add lateralsupport to the leader catheter 4, thereby preventing the leader catheter4 from buckling, these anti-buckling devices have length limitations andmay be too cumbersome and time-consuming for medical personnel toinstall.

Furthermore, emulating a manual guidewire manipulation in a roboticcatheter system is not a straightforward procedure. For example,although the instrument driver 1 illustrated in FIG. 1 can be designedto robotically insert/retract the guidewire 5 relative to the leadercatheter 4 in the same manner in which the instrument 1 roboticallyinserts/retracts the leader catheter 4 relative to the guide sheath 3,such an arrangement may be impractical. In particular, the incorporationof an additional carriage within the housing 2 will disadvantageouslyincrease the length of the instrument driver 1, which must accommodatethe telescoping assembly when assuming a maximum retraction between theleader catheter 4 and guide sheath 3 and between the guidewire 5 andleader catheter 4. The increased size of the instrument driver 1 may beimpractical and too big and heavy to be mounted on a table in a catheterlab environment. Thus, it is preferable that any drive device thatinserts/retracts the guidewire 5 relative to the leader catheter 4 beimmobile relative to the proximal end of the leader catheter 4, e.g., bylocating it on the same mounting plate 9 that is associated with theleader catheter 4. This drive device must also be capable of rolling theguidewire 5.

Furthermore, the use of an additional carriage for the guidewire 5 wouldalso require the installation of an additional “passive” anti-bucklingdevice. Because medical personnel often exchange out guidewires that areas long as 300 cm in length, the use of a “passive” anti-buckling devicenot only may be tedious for medical personnel to install, the extendedlength of the anti-buckling device due to the length of the guidewiremay render the anti-buckling device functionally impractical.

Additional complexities in emulating a manual guidewire manipulation ina robotic catheter system are slipping/buckling of the guidewire duringmanipulation and controlling or varying guidewire insertion/retractionspeeds depending on the procedure or task. Guidewires may also exist invarying conditions, for example a guidewire may be wet with saline, orcontaminated with blood or other bodily fluids. Many guidewires havehydrophilic coatings whose properties change with how dry or wet it is.In manual procedures, the doctor may adjust the grip on the wire toshorten it for higher force insertions to reduce risk of buckling.Alternatively, the doctor can lengthen the insertion strokes in times oflow insertion force where increased speed is desirable. The doctor mayalso use a wet cloth or dry cloth to wet or dry the wire, respectively,to alter the coefficient of friction on the wire to help with insertionor retraction

There, thus, remains a need to provide an improved instrument driver fora robotic catheter system that prevents a guidewire from buckling andimproves the control of guidewire manipulation.

SUMMARY

One exemplary embodiment of controlling an active drive system includesa drive assembly having a first surface and a second surface forengaging an elongate member. The first and second surfaces may beattached to a drive mechanism to move the elongate member. The firstsurface may be slidable relative to the drive mechanism and may have aclearance between the drive mechanism and an end of the first surfaceduring movement of the elongate member in a non-slip condition. A sensormay be associated with the first surface and may be configured to detectmovement of the first surface in a slip condition.

In another exemplary embodiment, a drive system for an elongate memberincludes an active drive device and a computing device. The active drivedevice may include a first surface and a second surface arranged on anactive drive mechanism for engaging the elongate member. The firstsurface may be axially slidable relative to the drive mechanism. A firstsensor may be associated with the first surface, and a second sensor maybe associated with the second surface, the sensors being configured tomeasure a force. The computing device may be in communication with theforce sensors. The computing device may be configured to compare thefirst sensor measured force with the second sensor measured force todetect a slip occurrence in one direction when the second sensormeasured force is not within a predetermined tolerance of the firstsensor measured force.

In a further exemplary embodiment, a slip detection system on a drivesystem includes a first surface, a second surface, and a computingdevice. The first surface may be configured to drive an elongate memberin an axial direction, and may include a first sensor configured todetect a force. The second surface may be axially movable relative tothe drive system, and may have a second sensor configured to detect aforce. The computing device may be configured to associate a thresholdforce with the second sensor, monitor the measured force on the secondsensor, and compare the measured force of the second sensor with thethreshold force to detect an initial slip occurrence between the activesurface and the elongate member in response to exceeding a predeterminedtolerance of the threshold force.

Additional embodiments and features are set forth in part in thedescription that follows, and will become apparent to those skilled inthe art upon examination of the specification or may be learned by thepractice of the disclosed subject matter. A further understanding of thenature and advantages of the present disclosure may be realized byreference to the remaining portions of the specification and thedrawings, which forms a part of this disclosure. One of skill in the artwill understand that each of the various aspects and features of thedisclosure may advantageously be used separately in some instances, orin combination with other aspects and features of the disclosure inother instances.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a robotic catheter system in accordance with apreferred embodiment;

FIGS. 2A-6 illustrate perspective views of an active drive apparatus inaccordance with a preferred embodiment;

FIGS. 7-10 illustrate perspective and elevation views of an active driveapparatus in accordance with an alternative preferred embodiment;

FIGS. 11-16 illustrate perspective, plan, and cross sectional views ofan active drive apparatus in accordance with an alternative preferredembodiment;

FIGS. 17-21 illustrate perspective and cross sectional views of anactive drive apparatus in accordance with an alternative preferredembodiment;

FIGS. 22 and 23 illustrate pad surfaces of a dynamic gripper of anactive drive apparatus in accordance with a preferred embodiment;

FIGS. 24 and 25 illustrate pad surfaces of a dynamic gripper of anactive drive apparatus in accordance with an alternative preferredembodiment;

FIGS. 26 and 27 illustrate pad surfaces of a dynamic gripper of anactive drive apparatus in accordance with an alternative preferredembodiment;

FIGS. 28 and 29 illustrate pad surfaces of a dynamic gripper of anactive drive apparatus in accordance with an alternative preferredembodiment;

FIGS. 30 and 31 illustrate top plan views of a debris cleaning/dryingmechanism in accordance with a preferred embodiment;

FIG. 32 illustrates a top plan view of a debris cleaning/dryingmechanism in accordance with an alternative preferred embodiment;

FIGS. 33 and 34 illustrate top plan views of a debris cleaning/dryingmechanism in accordance with an alternative preferred embodiment;

FIGS. 35 and 36 illustrate top plan views of a debris cleaning/dryingmechanism in accordance with an alternative preferred embodiment;

FIGS. 37 and 38 illustrate perspective and cross sectional views,respectively, of a debris cleaning/drying mechanism in accordance withan alternative preferred embodiment;

FIG. 39 illustrates a top plan view of a debris cleaning/dryingmechanism in accordance with an alternative preferred embodiment;

FIG. 40 illustrates a top plan view of a debris cleaning/dryingmechanism in accordance with an alternative preferred embodiment;

FIGS. 41 and 42 illustrate distinctive characteristics of the currentprofile of an insert motor and a grip motor, respectively, in accordancewith a preferred embodiment;

FIGS. 43A and 43B illustrate the respective positions of an insert motorand a gripper motor during one revolution or one full cycle/repetitionin accordance with a preferred embodiment;

FIG. 44 illustrates a process for aligning and synchronizing objects,such as motors, based on electrical current profiles and in accordancewith a preferred embodiment;

FIGS. 45 and 46 illustrate longer and shorter stroke lengths duringperiods of lower and higher insertion forces, respectively, inaccordance with a preferred embodiment;

FIGS. 47 and 48 illustrate the use of optical sensors to confirm if anelongate member is in a baseline condition or in a buckling condition inaccordance with a preferred embodiment;

FIG. 49 illustrates the use of a real-time imaging device to detect andprevent buckling of an elongate member in accordance with a preferredembodiment;

FIGS. 50A and 50B illustrate a slip detection system in accordance witha preferred embodiment;

FIG. 51 illustrates a process for slip and buckling detection andcorrection in accordance with a preferred embodiment;

FIGS. 52 and 53 illustrate cross sectional and perspective views,respectively, of a slip detection system in accordance with analternative preferred embodiment;

FIGS. 54 and 55 illustrate a slip detection system in accordance with analternative preferred embodiment;

FIGS. 56A and 56B illustrate distinctive characteristics of the currentprofile of sensors during conditions without slip and with slip inaccordance with a preferred embodiment;

FIGS. 57 and 58 illustrate a slip detection system in accordance with analternative preferred embodiment;

FIG. 59 illustrates a process for detecting slip in accordance with apreferred embodiment;

FIGS. 60-62 illustrate a slip detection system in accordance with analternative preferred embodiment; and

FIG. 63 illustrates a perspective view of a slip detection system inaccordance with an alternative preferred embodiment.

DETAILED DESCRIPTION

The following description of the preferred embodiments of the inventionis not intended to limit the disclosure to these preferred embodiments,but rather to enable any person skilled in the art to make and use thevarious embodiments described herein. Disclosed herein are devices,systems, and methods for implementing and controlling active drivesystems, as well as managing and preventing slip of the guide wire.

Described herein are devices, systems and methods for controlling activedrive systems and predicting and/or managing slip in active drivesystems. In general, active drive systems for gripping and manipulatingelongate members may include pad systems or roller systems. The pads orroller may have various diameters, widths, materials, or any otherphysical parameters. The elongate member may include a guidewire, asheath, a leader, a catheter, an endoscope, or any type of flexibleelongate medical instrument or tool. The terms guide wire and elongatemember are used interchangeably herein and are meant to cover thevarious types of wires, sheaths, leaders, catheters, endoscopes or thelike.

Active Drive Systems

Described below are four embodiments of active drive systems. In someembodiments, an active drive system may simultaneously insert/retractand roll an elongate member. Alternatively, an active drive system mayinsert/retract an elongate member independently of rolling the elongatemember. An active drive system may include two or more rollers and/ortwo or more gripping pads for inserting, retracting, and rolling anelongate member.

In some embodiments, an active drive system may be mounted to aninstrument driver 1, as shown in FIG. 1. Alternatively, an active drivesystem may be mounted to a separate arm, revolute joint, housing, orapparatus for manipulation and/or maneuverability of the active drivesystem.

Active Drive Systems with Rollers

FIGS. 2A-6 illustrate a first embodiment of an active drive apparatus,as described in pending U.S. patent application Ser. No. 13/835,136,filed Mar. 13, 2013, which is herein incorporated by reference in itsentirety. The drive apparatus 100 may function to provide continuousinsertion/retraction and rotation to an elongate member. In someembodiments, the active drive apparatus may include a roller assemblyand a roller support. In some embodiments, the roller assembly includesa first continuous surface, a second continuous surface, an openconfiguration for receiving an elongate member, and a closedconfiguration for securing the elongate member in the roller assembly.The roller assembly is configured to impart axial motion to the elongatemember along the first continuous surface. In some embodiments, thefirst continuous surface maintains contact with the elongate memberduring the axial motion. In some embodiments, the roller support isconfigured to rotate the roller assembly about the second continuoussurface, thereby imparting rotational motion to the elongate member. Thesecond continuous surface maintains contact with the roller supportduring the rotational motion. As will be described in further detailbelow, the roller assembly imparts the axial motion and the rollersupport imparts the rotational motion independently of one another, suchthat a first one of the roller assembly and the roller support impartsits associated motion regardless of a degree of motion imparted by theother of the roller assembly and the roller support.

In some embodiments, as shown in FIGS. 2A and 2B, the drive apparatus100 may further include a disposable mechanism 102 for contacting anddriving an elongate member, such that the disposable mechanism includesthe roller assembly. An associated drive mechanism 104 may generally beconfigured to be kept separate from the disposable mechanism 102, atleast to an extent allowing the drive mechanism 104 to be kept out of asterile environment associated with the elongate member and surgicalprocedure. As shown in FIGS. 2A-3, the disposable mechanism 102 may besupported between the roller support comprising two idle rollers 106,108, and a driving roller 110 which is configured to rotate thedisposable mechanism 102 about the second continuous surface to impartrotational motion to the elongate member.

As shown in FIG. 6, the roller assembly includes one or more rollers 112that are configured to impart axial motion to the elongate member alonga first continuous surface. For example, as shown in FIG. 6, a firstroller 112 a and a second roller 112 b each define generally cylindricalsurfaces 114 a, 114 b that are configured to maintain contact with theelongate member during axial motion caused by rotation of the rollers112. The drive apparatus 100 may further include a roller supportconfigured to rotate the roller assembly to impart rotational motion tothe elongate member. For example, as shown in FIGS. 4 and 5, the rollers112 may generally be supported within the clamps 116, 118 of thedisposable portion, for example via a saddle 120, as shown in FIG. 6, orby the clamps 116,118 themselves, such that the rollers 112 may berotated about an axis defined by the elongate member. It should be notedthat while one set of rollers 112 is shown, multiple sets of rollerscould be incorporated, for example in series, to provide additionaltraction on the elongate member for axial and rotational movementthereof. The clamps 116, 118 may be configured to receive an elongatemember into gap G in the open configuration, as shown in FIG. 4, and toclamp or secure the elongate member in the closed configuration, asshown in FIG. 5.

Referring now to FIG. 6, the disposable mechanism 102 is illustratedwith the left and right clamps 116, 118 removed. The disposable drivemechanism 102 includes a roller assembly including one or more rollers112 a, 112 b for imparting axial motion to the elongate member. As shownin FIG. 6, two rollers 112 a, 112 b may be configured to receive anelongate member therebetween. More specifically, the rollers 112 mayeach rotate about corresponding spindles 122 a, 122 b. Moreover, as willbe described further below, the rollers 112 a, 112 b may each have aplurality of geared teeth 124 a, 124 b which are meshingly engaged suchthat the rotation of the rollers 112 a, 112 b is generally coordinated.The rollers 112 a, 112 b may each be generally round, thereby definingrespective continuous surfaces 114 a, 114 b about the generallycylindrical rollers 112 for engaging the elongate member. Morespecifically, an axial movement of any distance may be applied by therollers 112 a, 112 b, since the rollers 112 a, 112 b may continuouslyturn about the spindles 122 without limitation. Accordingly, axialmotion of the elongate member is not limited by any range of motion ofany component of the drive apparatus 100, allowing the drive apparatus100 to provide an axial movement in either direction of any magnitudewhile maintaining constant contact with the elongate member by way ofthe generally looped or continuous surfaces 114 a, 114 b of the rollers112 a, 112 b.

The roller assembly may be supported in a roller support configured torotate the rollers about an axis perpendicular to the spindles 122 ofthe rollers 112. For example, the spindle 122 a of the roller 112 a maybe supported in a saddle 120 that is engaged with an interior surface ofone of the clamps 116, 118 (not shown in FIG. 6) by way of a pluralityof springs 126. Radially inward movement of the saddle 120 away from theinterior surface may be limited by stop pins 128, which may engage aninterior side of the saddle 120 to generally limit radially inwardmovement of the saddle 120 and the roller 112 a, thereby limiting forceapplied by the roller 112 a to the elongate member when the elongatemember is positioned between the rollers 112 a, 112 b. The spindle 122 bof the other roller 112 b may be supported in the corresponding one ofthe clamps 116, 118 (not shown in FIG. 6). Accordingly, the spindle 122b may be generally fixed within the clamps 116, 118 while the spindle122 a may be movable by way of the springs 126 to provide a clampingforce upon the elongate member.

The disposable device 102 may further comprise gear halves 128 a, 128 bwhich define an inner toothed surface 130 engaging a drive pinion 132,as shown in FIGS. 4 and 5. The drive pinion 132 may be engaged with aworm gear 134 by way of worm 136, wherein the worm 136 is fixed forrotation with the drive pinion 132. A location shaft 138 may be providedto assist with locating the above components within the clamps 116, 118,as will be described further below. Additionally, a compliant element140 may be provided which generally provides a spring force urging theclamps 116, 118 toward an open position, as shown in FIG. 4.

Active Drive Systems with Pads/Grippers

FIGS. 7-10 illustrate a second alternative embodiment of an active drivemechanism, for example an active catheter feeder 200, as described inpending U.S. patent application Ser. No. 13/803,535, filed Mar. 14,2013, which is herein incorporated by reference in its entirety. Thecatheter feeder 200 is designed to mimic the manual finger feed methodthat physicians may use to advance/retract the leader catheter withinthe guide sheath, and in particular, the grip, push, release,retracting, and repeating movements performed by the fingers of thephysician to incrementally advance the leader catheter, and the grip,pull, release, advancing, and repeating movements performed by thefingers of the physician to incrementally retract the leader catheter.

As shown in FIGS. 7-8, the catheter feeder 200 generally comprises afeeder assembly 202 configured for advancing/retracting the leadercatheter within the guide sheath, a grip adjustment assembly 204configured for adjusting the grip of the feeder assembly 202, aloading/unloading assembly 206 configured tier allowing the leadercatheter to be top-loaded and unloaded from the active catheter feeder200, a base plate 208 on which the feeder assembly 202 and, gripadjustment assembly 204 are mounted, a housing 210 mounted to the baseplate 208 over the feeder assembly 202 and grip adjustment assembly 204,and a drape 212 configured for isolating the disposable components ofthe catheter feeder 200 from the sterile field. The feeder assembly 202generally comprises a grip assembly arrangement 214 configured forperforming advancing/retracting movements of the leader catheter, and adriver assembly 216 configured for actuating the grip assemblyarrangement 214 to perform these movements.

Referring further to FIG. 8, the grip assembly arrangement 214 includesthree grip assemblies 218 a, 218 b, 218 c configured for beingindependently translated relative to the base plate 208 parallel to alongitudinal axis 220 in a reciprocal manner. To this end, the gripassemblies 218 are slidably engaged with each other in a nestedarrangement. In order to guide independent translation of the gripassemblies 218 along the longitudinal axis 220, the grip assemblyarrangement 214 further includes a parallel pair of rails mounted to thebase plate 208 along the longitudinal axis 220.

As shown in FIGS. 9 and 10, the grip assembly 218 is configured forbeing alternately closed (FIG. 9) to grip the catheter body 224 betweenthe respective gripping pads 226, 228 of the first and second grippers230, 232, and opened (FIG. 10) to release the catheter body 224 frombetween the respective gripping pads 226, 228 of the first and secondgrippers 230, 232. For the purposes of this specification, a gripassembly is closed at the point where the gripping pads 226, 228 areclosest to each other, and is open at the point where the gripping pads226, 228 are furthest from each other (after the second grippers 232 areadjusted to a fixed position by the grip adjustment assembly 204 usinggrip actuator 234). The grip assembly 218 is designed in a manner thatthe catheter body 224 is only gripped when the grip assembly 218 is inthe closed position, and the catheter body 224 is released when the gripassembly 218 is in the opened position or transitioning between theclosed position and the opened position. Furthermore, the gripadjustment assembly 204, as shown in FIG. 8, can be operated to adjustthe strength that the grip assembly 218 grips the catheter body 224between the gripping pads 226, 228.

In the third and fourth alternative embodiments described below, axialand rotational motion of the elongate member may be governed byindependent drive systems associated with the drive apparatus. Forexample, a dynamic gripper may have separate motors or mechanismscontrolling axial motion on the one hand and rotational motion on theother. Accordingly, insertion and rotation of the elongate member may beaccomplished completely independently of the other. More specifically,the elongate member may be inserted axially while it is being rotated,or the elongate member may be inserted without any rotation. Moreover,the elongate member may be rotated without requiring any insertionmotion at the same time.

FIGS. 11-16 illustrate a third alternative embodiment of an active drivedevice 300, as described in pending U.S. patent application Ser. No.13/838,777, filed Mar. 15, 2013, herein incorporated by reference in itsentirety. In the illustrated example, the drive apparatus includes astatic gripper 302, and a dynamic gripper 304. In some embodiments, thestatic gripper 302 may be generally fixed with respect to a supportsurface 306. Each of the grippers 302, 304 may comprise a clamp 308, 310having a pair of opposing pads 312 a, 312 b and 314 a, 314 b,respectively. Accordingly, the grippers 302, 304 may each selectivelyclamp an elongate member, e.g., a guidewire or catheter, between theirrespective opposing pads 312 a, 312 b and 314 a, 314 b. The dynamicgripper 304 may have a range of motion to which it is confined. Forexample, the dynamic gripper 304 may be capable of axial movement in adirection A along a distance D. Additionally, the dynamic gripper 304may be capable of limited rotational movement about an axis parallel tothe direction of axial movement, for example to a range of plus or minusa predetermined angle with respect to a normal or center position. Thedynamic gripper 304 may move an elongate member across a predeterminedmovement, for example an axial or rotational movement that may beprovided by a user that is greater than the axial or rotational range ofmotion.

As shown in FIG. 11, the grippers may each be mounted to the supportstructure 306, for example a top surface or support structure associatedwith the instrument driver. The dynamic gripper 304 is configured togenerally move axially and rotationally with respect to the supportstructure 306 to effect a corresponding axial and rotational movement ofthe elongate member. By contrast, the static gripper 302 is generallynot movable axially or rotationally with respect to the supportstructure 306. The static gripper 302 selectively closes and opens togrip and release the elongate member. In some embodiments, the staticgripper 302 cooperates with the dynamic gripper 304 to effect axialmovement (i.e., for insertion) along a direction A as illustrated inFIG. 11, and rotational movement R about the direction A of the elongatemember. The grippers 302, 304 may generally work in sequence such thatat least one of the grippers 302, 304 is gripping the elongate member atany given time. More specifically, during any movement of the guidewire,for example insertion, retraction, or rotational movement in eitherdirection, the dynamic grippers 304 are closed, and static grippers 302are open.

A range of axial motion associated with the dynamic grippers 304 may befinite, and in particular be limited to a predetermined axial distanceD, as shown in FIG. 13. Accordingly, upon reaching a limit to the rangeof motion, for example at an axially furthest position in one direction,the dynamic grippers 304 generally release the elongate member, moveback in an opposite direction, and re-grip the elongate member forcontinued axial movement. While the dynamic grippers 304 are notgripping the elongate member, the static grippers 302 may hold theelongate member in place to prevent movement or loss of position.Further, the static and dynamic grippers 302, 304 may each be configuredto open to allow loading of an elongate member.

Turning now to FIGS. 15 and 16, rotational motion of the dynamicgrippers 304 is described and shown in further detail. A rotation drivemotor 316, as best seen in FIG. 15, may rotate a gear 318 engaging acarriage or swing platform 320 configured to rotate about an axis ofrotation, for example in a rotational motion R about the direction ofinsertion A. The carriage 320 may be located by a pair of rolling posts322 supported by a base structure 324. The base structure 324 may inturn be secured to the support structure 306. The carriage or swingplatform 320 may be capable of rolling from a nominal or center positionto any degree that is convenient.

FIGS. 17-21 illustrate a fourth alternative embodiment of an activedrive apparatus 400, as described in pending U.S. patent applicationSer. No. 13/838,777, filed Mar. 15, 2013, herein incorporated byreference in its entirety. The drive apparatus 400 may generally includea dynamic gripper 404 and two static grippers 402 a, 402 b. The dynamicgripper 404 may comprise a pair of opposing pads 406, 408. Similarly,the first static gripper 402 a may comprise a pair of opposing pads 410a, 412 a, and the second static gripper 402 b may also comprise a pairof opposing pads 410 b,412 b. Accordingly, the grippers 404, 402 a, and402 b may each selectively grip an elongate member between theirrespective opposing pads 406/408, 410 a/412 a, and 410 b/412 b. The pads406/408, 410 a/412 a, and 410 b/412 b may each be relatively soft withrespect to the particular elongate member being employed, in order tomore securely grip the elongate member and minimize potential damage tothe elongate member, for example by spreading grip load across anincreased surface area of the elongate member.

As shown in FIG. 17, the static grippers 492 a, 402 b and dynamicgripper 494 may each be mounted to a support structure 414, for examplea top surface or support structure associated with the instrumentdriver. The dynamic gripper 404 is configured to generally move axiallywith respect to the support structure 414 to effect a correspondingaxial movement of the elongate member. The pads 406, 408 of the dynamicgripper 404 are also configured to translate in a vertical directionacross a fixed range of motion to impart rotational motion to theelongate member with respect to the support structure 414. By contrast,the static grippers 402 a and 402 b are generally not movable axially orrotationally with respect to the support structure 414. The staticgrippers 402 a and 402 b selectively close and open to grip and releasethe elongate member.

Generally, similar to the drive apparatus 300 described above, thestatic grippers 402 a and 402 b of the drive apparatus 400 eachcooperate with the dynamic gripper 404 to effect axial movement (i.e.,for insertion or retraction) along a direction A, as illustrated in FIG.17, and rotational movement R about the direction A of the elongatemember. The static grippers 402 a, 402 b may generally work in sequencewith the dynamic grippers 404 such that at least one of the grippers404, 402 a, and 402 b is gripping the elongate member at any given time.More specifically, during any movement of the guidewire, e.g.,insertion, retraction, or rotational movement in either direction, thedynamic grippers 404 are closed, and the static grippers 402 a and 402 bare open. Moreover, the static grippers 402 a, 402 b may generally workin concert, such that the static grippers 402 a, 402 b are either bothopen or closed.

A range of axial motion associated with the dynamic grippers 404 may befinite, and in particular be limited to a predetermined axial distanceD₂, as seen in FIG. 17. In the illustrated example having two staticgrippers 402 a, 402 b, a range of motion of the dynamic gripper 404 maybe limited by the static gripper 402 a on one end and the other staticgripper 402 b on the other end. However, as noted above, in otherembodiments, only one static gripper 402 may be present, and thus theaxial motion of the dynamic gripper 404 may be limited by other factors.Nevertheless, the dynamic gripper 404 may have some predetermined rangeof axial motion. Accordingly, upon reaching a limit to the range ofmotion at an axially furthest position in one direction, the dynamicgrippers 404 generally release the elongate member, move back in anopposite direction, and re-grip the elongate member for continued axialmovement. While the dynamic grippers 404 are not gripping the elongatemember, the static grippers 402 a and/or 402 b may hold the elongatemember in place to prevent movement of the elongate member or loss ofposition. This synchronization of the movement of the dynamic and staticgrippers is described in further detail below in the section“Synchronizing and Aligning Active Drive Motors.”

Pads 406 and 408 may be designed to optimize the gripping and rollingperformance of the elongate member. For example, in one embodiment, ahigh durometer material that does not engulf the elongate member isused, which may generally prevent pads 406 and 408 from contacting eachother. This ensures that the spring force closing the grippers issubstantially entirely applied to the elongate member and is nottransferred from one gripper to the other, ensuring reliable grip on theelongate member. In another embodiment, the contact surface of the pads406 and 408 is beveled in a convex shape such that there is less chancethat the pads will contact each other due to any misalignment ornon-parallelism in the gripper mechanism. Different pad materials andconfigurations will be described in further detail below in the section“Active Drive System Enhancements.”

During axial movement of the elongate member and also during rotationalmovement, the dynamic pads 406 and 408 are generally closed, therebytrapping the elongate member there between as a result of a gripimparted to the elongate member. Additionally, during axial orrotational motion of the elongate member, the pads 410 a, 412 a of thefirst static gripper 402 a and the pads 410 b, 412 b of the secondstatic gripper 402 b remain open, thereby generally freely allowingrelative movement of the elongate member with respect to the staticgrippers 402 a, 402 b. Upon reaching a limit of rotational or axialmotion, the pads 410 a, 412 a of the first static gripper 402 a and thepads 410 b, 412 b of the second static gripper 402 b may be closed. Thepads 406 and 408 of the dynamic gripper 404 may then be opened, andmoved within its range of motion (i.e., along distance D) to allowregripping of the elongate member, while the static grippers 402 a, 402b maintain the axial and rotational position of the elongate member. Thecycle may then be repeated to allow further axial and/or rotationalmovement of the elongate member.

In some embodiments of active drive devices described above, an elongatemember may be wrapped at least partially about a slip detection wheel326, as shown in FIG. 11, or 416, as shown in FIG. 17, that passivelyrotates in response to a length of the guidewire being moved by thedynamic grippers 304,404, respectively. The slip detection wheel 326/416may be mounted on a rotatable member 328/418. Moreover, as will bedescribed further below, the wheel 326/416 may include optical marksallowing for tracking of the wheel 326/416 rotation, thereby allowingmeasurement of movement and/or slippage of the elongate member.

Active Drive Systems Enhancements

In some embodiments described above, the active drive system may includepads coupled to grippers configured for manipulating elongate members ofvarious sizes, diameters, or configurations. For example, as shown inFIGS. 22-23, the pads of an active drive system 400 may includemulti-durometer pad sections 420, 422 configured to manipulate smallerand larger elongate members 424, respectively. The multi-durometer padsections may manipulate elongate members including a diameter between0.250 inches and 0.010 inches or any subrange therebetween, For example,an elongate member diameter may include 0.150 inches, 0.035 inches,0.025 inches, 0.020 inches, 0.018 inches, 0.014 inches, less than 0.014inches, or any diameter suitable to the application. To accommodate forvarious sizes, the drive apparatus may further be configured to receivea user input allowing selection of a size of the elongate member 424 ormay automatically detect a size of the elongate member 424 using one ormore sensors, for example optical sensors.

As shown in FIGS. 22-23, pad 406/408 may include pad section 420 a(e.g., shown as an upper section) made of a harder durometer materialand pad section 422 a (e.g., shown as a lower section) made of a softerdurometer material. Depending on the size of the elongate member 424 tobe manipulated, pad 406/408 may be oriented in a first configuration, asshown in FIG. 22, with a central portion of the selected pad section 420a aligned with an eyelet 426 of a central portion of pad 410/412, forexample providing a harder durometer pad surface for smaller wires orcatheters. For another size elongate member 424, pad 406/408 may beoriented in a second configuration, as shown in FIG. 23, with a centralportion of pad section 422 a aligned with eyelet 426, for exampleproviding a softer durometer pad surface for larger wires or catheters.Thus, depending on the determined size of the elongate member 424, thedrive apparatus 400 may align either pad section 420 a or 422 a witheyelet 426 for receipt of elongate member 424.

As shown in FIGS. 24-25, pad 406/408 may be patterned with strips ofinterlocking and alternating pad sections 420 b and 422 b, for examplewhere pad sections 422 b are raised (e.g., configured as teeth). In anengaged configuration as shown in FIG. 24, pads 406/408 may create amechanical lock on elongate member 424 to increase grip during insertionor retraction of elongate member 424. The strips may be configured asteeth that are dimensioned and spaced such that a smaller (e.g., 0.014inch diameter) elongate member 424 contacts pad sections 420 b and 422 b(e.g., harder and softer durometer sections) while a larger (e.g., 0.035inch diameter) elongate member 424 will primarily contact pad sections422 b (e.g., softer durometer). The strips may further be dimensionedand spaced to reduce kinking of elongate member 424. Thus, this mayallow for rolling of smaller wires without encapsulation whilemaintaining grip for insertion of larger elongate members 424.

As shown in FIGS. 26-27, a pad surface of the dynamic gripper alternatesbetween harder and softer (e.g., higher and lower durometers) sections420 c, 422 c. For example, the alternation of low and high durometers onthe surface of and between pads 406/408 may prevent pads 406/408 frombinding against each other, e.g., with lower durometer materials oncontacting pad sections 422 c. During insertion/retraction, pad sections422 c (e.g., softer durometer) will slightly deform around elongatemember 424 thereby increasing grip. When rolling elongate member 424 onan active drive design described in U.S. Nonprovisional patentapplication Ser. No. 13/838,777, which is herein incorporated byreference, and described in paragraph 0040, the pads translate withrespect to each other. Therefore, section 420 c (e.g., harder durometer)will have to exert enough sheer force on elongate member 424 to breakthe friction forces between the pad sections 422 c (e.g., softerdurometer) and elongate member 424. However, after the friction forcesare met or exceeded, elongate member 424 may roll with pad sections 422c in a deformed condition.

Referring to FIGS. 28-29, pad section 420 d (e.g., harder durometer) mayhave one, two (shown), or more insets 428, which may be on oppositesides of a central portion of pad section 420 d. Inset 428 a may have asmaller radius (e.g., 0.01 inches for 0.014 and 0.018 inch diameterguide wires) and inset 428 b may have a larger radius (e.g., 0.018inches for 0.035 inch diameter guide wires). Insets 428 a, 428 b may benear a central portion of pad section 420 d, for example, so elongatemembers 424 may pass through eyelets 426 of pads 410/412 withoutrepositioning pad sections 420 d, 422 d to the first and secondconfigurations, discussed above with respect to FIGS. 22-23. Pad section422 d (e.g., softer durometer) may provide grip for insertion andretraction of elongate member 424.

Alternative embodiments may have any number of other or additionalfeatures. For example, pads 406/408 may be made of a single durometermaterial including surface features (e.g., patterns, treads, or grooves)to optimize grip for elongate members 424 of all sizes. Further, pads406/408 may include micro fibers or any other material with a highcoefficient of friction, an ability to wick liquids, or an elasticity orlack of deformation under pressure. Moreover, pads 406/408 may includeconcave or convex surfaces, for example, to concentrate the forces to adesired line of contact between elongate member 424 and pads 406/408.

In some embodiments, an active drive system may include a guide wire orcatheter drying or cleaning mechanism. Many guidewires have a wettablelow friction hydrophilic coating. This coating absorbs moisture from theenvironment and produces a hydrogel which gives a low friction surfaceto the guidewire to help the physician advance the guidewire through theanatomy with low force. The guidewire drying mechanism absorbs themoisture from the hydrogel thereby removing the lubricous surface andincreasing the friction. The guide wire drying mechanism thereby helpsto reduce or eliminate guide wire slippage due to blood, plasma, saline,water, thrombus, and/or other materials and fluids. The drying orcleaning mechanism also removes debris and other unwanted materials, toensure a better grip for the drive mechanism during roll, retraction,and/or insertion of the guide wire into the patient. The dryingmechanism may include a debris-cleaning member and a holder for holdingthe debris-cleaning member against the guide wire and optionallyclamping the debris-cleaning member against the guide wire.

In one embodiment, the debris-cleaning member includes one or moreabsorbent pads, such as gauze, foam, cotton, or the like, that act toabsorb fluids and debris from the guide wire. The absorbent pads aretypically positioned distal of (i.e. closer to the patient) the dynamicgrippers or drive mechanism, so that the guide wire is cleaned and/ordried prior to reaching the drive/gripper components. For example, theabsorbent pads may be connected to a separate component positionedbetween the drive component and the exit of the guide wire/catheter fromthe patient. In another example, the absorbent pads are integrated withthe drive component, but positioned distal of the dynamic grippers.

In another embodiment, the debris-cleaning member may include a wiper orwicking element that wicks fluid and debris from the guide wire. Thewiper can be used with or without the absorbent pads. For example, thewiper may be positioned in front of the absorbent pad to reduce thefluids reaching the absorbent pad and extend the useful life of the pad.As another example, the wiper may be positioned prior to the guide wireentering a drive component and may optionally include a vacuum orsuction mechanism positioned adjacent to the guide wire (e.g., above orbelow the guide wire) that pulls the debris falling off the guide wiredue to the wipers.

In yet another embodiment, the debris cleaning mechanism may include asuction or drying element. For example, a suctioning or vacuum componentmay be positioned at a location so as to reach the guide wire before itenters the drive mechanism. The suctioning or vacuuming component actsto pull debris (via a vacuum force) off of the wire. As another example,a heating element can be used to evaporate or dry the fluid so that thefrictional coefficient of the gripping wire is increased.

By using the debris cleaning or drying mechanisms described herein,guide wires and catheters used for catheter procedures and othertherapies may be less prone to slippage, reducing risks and injuriesthat can result from slippage, especially with hydrophillically coateddevices that become very slippery when wet, which can increase the sliprisk as the guide wire may not be held securely by either the staticgrippers or dynamic grippers when wet. Additionally, the debris cleaningmechanisms disclosed herein are automated or otherwise do not requireuser intervention or manipulation to operate. On the contrary, inconventional products, the physician may manually dry or clean the guidewire during refraction, which not only can complicate the procedureand/or workflow, but also increases the procedure time. Further, becauseof the drawbacks to manual cleaning by a physician or other worker,cleaning is typically only done after slippage has already occurred,which means that the guide wire has already lost position during acatheter exchange, therapy delivery, or the like, i.e., a potentialinjury or error may have already occurred before cleaning is completed.As the drying mechanism does not require a doctor or other user'sattention or activation, the drying mechanism can be used during allstages of a procedure, helping to prevent slippage before it occurs,reducing the risks associated with slippage, and helping to reduceprocedure time and complexity.

Turning back now to the figures, various examples of the debris cleaningor drying mechanism will now be discussed in more detail. FIG. 30 is atop plan view of the debris cleaning/drying mechanism 500 in the openposition. FIG. 31 is a top plan view of the debris cleaning mechanism500 in the closed or clamped position. With reference to FIGS. 30 and31, the debris cleaning mechanism 500 in this example includes twoopposing cleaning clamps 502 positioned on opposite sides of a guidewire 504. The cleaning/drying clamps 502 may be positioned adjacent to adrive mechanism, such as the active drive mechanisms shown in FIGS.2A-21, other active drive mechanisms, and/or passive drive mechanisms.Depending on whether cleaning is desired during retraction or insertion,the cleaning clamps 502 may be positioned on either the distal orproximal side of the drive mechanism relative to the insertion pointwithin the patient. That said, in many embodiments, the cleaning/dryingclamps 502 will be positioned between the insertion point within thepatient and the drive mechanism to clean/dry the guide wire 504 after itexits the patient during retraction and prior to entering the drivemechanism.

With continued reference to FIGS. 30 and 31, the two cleaning/dryingclamps 502 may be substantially the same as one another and each mayinclude a pad holder 506 and one or more absorbent pads 508. The padholder 506 holds the absorbent pads 508 and may optionally be configuredto selectively clamp and unclamp the absorbent pads 508 against theguide wire 504. For example, the pad holders 506 may be connected to anactive drive mechanism or may otherwise include a motorized power sourcethat can move the pad holder 506 from a first or open position to asecond or closed position. The pad holders 506 may also include bracketsor other securing elements for securing the absorbent pads 508.Depending on the configuration of the brackets or securing elements, theabsorbent pads 508 may be permanently attached to brackets or may beselectively removable from the pad holders 506.

The absorbent pads 508 are substantially any type of material that canabsorb fluids and preferably is any type of absorbent material that doesnot shed fibers. For example, the absorbent pads 508 may be formed ofgauze, microfiber, cotton, polyester, foam, synthetic fabric, porousrubber, or the like. The shape and configuration of the absorbent pads508 may be varied as desired, which may depend on the type of procedurebeing performed, the diameter of the guide wire or catheter, the type ofguide wire or catheter, the type of valve on the catheter, the type ofdrive system, or the like.

In some embodiments, the absorbent pads 508 include a barrier or dryingsurface. The barrier is a separate material from the absorbent pads,such as a coating, film, or the like, that acts to filter the fluids anddebris absorbed into the absorbent pads 508 and/or help prevent theabsorbent pads 508 from sticking to the guide wire 504, while stillallowing fluids to pass therethrough to be absorbed by the pad. Forexample, the drying surface may be a porous-polymer coating, mesh, orthe like.

Operation of the debris cleaning/drying mechanism 500 of FIGS. 30 and 31will now be discussed in more detail. With reference to FIG. 30, thedebris cleaning mechanism 500 is in the open position and the cleaningclamps 502 are spaced apart from the guide wire 504. In this position,the guide wire 504 can easily pass between the cleaning clamps 502 asthe absorbent pads 508 do not touch or are in light to no contact withthe guide wire 504. This allows the guide wire 504 to be more easilyrepositioned by the drive mechanism as the cleaning clamps 502 do notexert any friction on the guide wire 504 in this configuration. Withreference to FIG. 31, after the guide wire 504 has been repositioned toa desired location, the cleaning clamps 502 may be moved to the closedposition, so that the absorbent pads 508 are in full contact with theguide wire 504. In this position, fluids from the guide wire 504 areabsorbed into the absorbent pad 508 and where the barrier is included,travel through pores into the barrier and into the pad 508. As fluidsand other debris are absorbed into the pads 508, they are removed fromthe guide wire 504, increasing the coefficient of friction of the guidewire 504 by cleaning/drying the guide wire 504 to help prevent slippagewhen the guide wire 504 is received into the drive mechanism.

In the embodiment shown in FIGS. 30 and 31, the selective positioning ofthe cleaning clamps 502 relative to the guide wire 504 is used to reducethe potential of the absorbent pads 508 from interfering with movementof the guide wire 504 by the drive mechanism. However, depending on thetype of material used for the absorbent pads 508 and/or barrier, thecleaning clamps 502 may be arranged to be engaged with the guide wire504 during repositioning of the guide wire 504, i.e., in a permanentlyclamped position. For example, the barrier may have a sufficiently lowcoefficient friction such that the guide wire 504 can move along thebarrier surface unobstructed when moved by the drive mechanism even whenthe absorbent pads 508 are clamped together. In this orientation, thecleaning clamps 502 may only be opened during the initial threading orinsertion of the guide wire 504.

In some instances the absorbent pads 508 may be removable andreplaceable from the cleaning clamps 502. FIG. 32 illustrates anotherexample of the debris cleaning mechanism. With reference to FIG. 32, inthis embodiment, the pad holders may form brackets defining a pad cavity610 or recess and the absorbent pads 608 may be positioned in the padcavity 610 and constrained from movement by the edges of the pad holders606. In this example, the top and/or bottom ends of the pad holders 606may be open to allow the absorbent pads 608 to be slid into and out ofthe pad cavity 610. The absorbent pads AA may be modified to match theshape of the pad holders or alternatively the pad holders may bemodified to match the shape of the absorbent materials. As one example,a gauze roll may be used as the absorbent pad and the cylindrical rollmay be inserted into the pad holder 606 and easily removed whensaturated without substantially disrupting the guide wire 604 or thedrive assembly. In the example shown in FIG. 32, the absorbent pads maybe static and may be positioned sufficiently close to the guide wire 604so that the guide wire 604 engages with at least one and preferably bothabsorbent pads 608 as it is moved by the drive assembly. Alternatively,the cleaning clamps 602 may be configured as in FIGS. 30 and 31 so thatthe pad holders 606 are selectively moved closer together and fartherapart to clamp and unclamp around the guide wire/catheter.

In the embodiments shown in FIGS. 30-32, the debris cleaning mechanismis separate from the driving and/or clamping mechanisms of the catheterinsertion assembly or system. However, in other embodiments the debriscleaning mechanism is incorporated into the static gripper mechanism.FIG. 33 is a top plan view of a debris cleaning mechanism integratedinto a static gripper mechanism in the open position. FIG. 34 is a topplan view of the debris cleaning mechanism of FIG. 33 in the closed orclamped position. With reference to FIGS. 33 and 34, the dryingmechanism 700 may be substantially the same as the drying mechanisms500,600, but in this example, the cleaning/drying clamps 702 may includethe absorbent pads 708 and the gripper pads 712. The gripper pads 712and the absorbent pads 708 may both be positioned on a front face of thecleaning clamps 702 and oriented to face the corresponding pads on theopposite cleaning clamp. That is, the absorbent pad 708 for the firstcleaning clamp 702 a is positioned across from the absorbent pad 708 ofthe second cleaning clamp 702 b and likewise the gripper pad 712 for thefirst cleaning clamp 702 a is positioned across from the gripper pad 712for the second cleaning clamp 702 b. In one embodiment, the absorbentpads 708 are positioned distal of the gripper pads 712, so that theguide wire 704 is cleaned as it exits the patient's body or catheter andbefore it reaches gripper pads 712. In some embodiments the absorbentpads 708 are spaced apart from the gripper pads 712 to define a gapbetween the two pads. However, in other embodiments, the absorbent pads708 and the gripper pads 712 on each cleaning/drying clamp 702 arepositioned adjacent to and touching one another.

With continued reference to FIGS. 33 and 34, the gripper pads 712 inthis embodiment may be substantially the same as the other gripper padsdisclosed herein. Additionally, the cleaning clamps may be driven bysimilar active drive mechanisms as disclosed herein, with the exceptionbeing that the cleaning clamps may also include brackets for holding theabsorbent pads. Depending on the materials used for the absorbent pads708 and the gripper pads 712 the thickness of each of the pads 708, 712may be the same or may be varied. For example, in one embodiment, theabsorbent pads 708 may be more easily deformed than the gripper pads 712and in this example, the absorbent pads 708 may have a first thicknessT1 and the gripper pads 712 may have a second thickness T2 where T2 isgreater than T1. If the absorbent pads are on the same clamp as thedynamic gripper pad, T2 is used such that when the clamps are in theopen position, the absorbent pads remain in contact with the wire suchthat they serve to clean/dry the wire in the return stroke while thedynamic gripper is open. Continuing with this example, as the absorbentpads 708 deform more readily and in the clamped position (see FIG. 34),the absorbent pads 708 deform to the same thickness as the dynamicgripper pads 712. However, in other embodiments, if the absorbent padsare on the same clamp as the static gripper pad, the static gripper pads712 and the absorbent pads 708 may have the same thicknesses or thestatic gripper pads 712 may have a greater thickness as compared to theabsorbent pads 708.

Operation of the drying mechanism 700 of FIGS. 33 and 34, will now bediscussed in more detail. Generally, the operation of the dryingmechanism 700 may be substantially the same as the drying mechanism 500of FIGS. 30 and 31, however, as the cleaning clamps 702 are moved, theguide wire 704 is repositioned by the dynamic gripper pads 712. Inparticular, in the open position of the cleaning clamps as shown in FIG.33, the static gripper pads (not shown in FIG. 33) secure the guide wire704 to hold it in a desired position and the dynamic gripper pads 712may be repositioned relative to the wire. For example, the entirecleaning clamp 702 may be repositioned relative to the guide wire 704 tomove the guide wire 704 to a different location relative to the grippingsurface of the gripper pads 712 and absorbent pads 708. Alternativelythe pads 712 themselves may be moved relative to the pad holders 706 toreposition the guide wire 704.

With reference to FIG. 34, after the gripper pads 712 have beenrepositioned as desired, the debris cleaning mechanism 700 transitionsto the clamped position. In the clamped position, the absorbent pads 708and the gripper pads 712 are moved to clamp against the guide wire 704.As the absorbent pads 708 clamp against the guide wire, they act toabsorb fluids from the guide wire 704, cleaning and drying the guidewire 704.

In the debris cleaning mechanism 700 of FIGS. 33 and 34, the absorbentpads 708 and/or the gripper pads 712 may be removable and replaceable.For example, the two sets of pads may be removed and replaced in a set.As another example, the pads may be individually replaceable. In thisexample, waste may be reduced since the absorbent pads may need to bereplaced more frequently than the gripper pads and can be removed andreplaced when needed, without requiring the gripper pads to be replacedas well.

Although in the embodiment shown in FIGS. 33 and 34 the absorbent pads708 and the gripper pads 712 are shown as two separate components, inother embodiments, the absorbent pads 708 and the static gripping pads712 may be integrated into a single component. For example, a firstportion of an integrated absorbing and static gripping pad may have anabsorbent material and a second portion of the pad may include agripping material for gripping the guide wire. In another example, asingle material may be sufficiently absorbent and with a sufficientlyhigh coefficient of friction to grip the guide wire, while also removingfluids from the wire. Similarly, although the embodiment of FIGS. 33 and34 have been discussed with respect to a single absorbent pad and asingle gripping pad on each cleaning clamp 702, in other embodiments,the drying mechanism may include two or more of each pad on each clamp.

In addition to or alternatively to the absorbent pads, the dryingmechanism may also include a wick or wiper. FIGS. 35 and 36 illustratetop plan views of a drying mechanism including both a wiper and anabsorbent pad. With reference to FIGS. 35 and 36, the drying mechanism800 of this embodiment may be substantially similar to the dryingmechanism of FIGS. 30 and 31, but may also include a wiper 814. Thewiper 814 may be positioned distal of the absorbent pad 808 so that asthe guide wire 804 is retracted, the wiper 814 reaches the guide wirebefore the absorbent pad 808. In other words, in the retractiondirection D_(R), the wiper is positioned in front of the absorbent pad808.

The wiper 814 may be substantially any type of flexible material, suchas rubber, silicone, or the like. The wiper 814 wicks fluid and debrisoff of the guide wire 804. The wiper 814 can be used on its own, or asshown in FIGS. 35 and 36, may be used in combination with the absorbentpads. In examples where the wiper is used with the absorbent pads, wiper814 helps to prolong the life of the absorbent pads as more of thefluids and debris are wiped off of the guide wire 804 before the guidewire 804 reaches the absorbent pad 808. This allows the absorbent pad808 to absorb fewer fluids and debris, while also increasing the overalldryness of the guide wire 804 as two separate drying mechanisms areused. In other words, the wiper 814 may act as a squeegee to removedebris from the outer surface of the guide wire 804 which works intandem with the absorbent pads to fully dry the guide wire.

With reference to FIG. 35, the wiper 814 may be sufficiently flexible sothat in the clamped or closed position of the drying mechanism the wipermay deform as it presses against the guide wire 804. This characteristicallows the cleaning clamps to be clamp sufficiently close to the guidewire 804 and each other that the guide wire 804 engages with the wiper814 to ensure that the guide wire 804 can move relative to the wiperwhen needed, but is also sufficiently engaged to allow fluids to beremoved from its outer surface.

As briefly mentioned above, in some embodiments, the debris cleaningmechanism includes replaceable absorbent pads and/or wipers. FIG. 37illustrates a perspective view of a debris cleaning mechanism with areplaceable cleaning clamp. FIG. 38 is a cross-section view of thedebris cleaning mechanism of FIG. 37 taken along line 38-38 in FIG. 37.With reference to FIGS. 37 and 38, in this example, the debris cleaningmechanism 900 may include an enclosed cleaning clamp 902 housing one ormore absorbent pads 908 and/or wipers 914. In particular, the cleaningclamp 902 includes a housing 916 having a wiper aperture 918 definedtherethrough and having a lead-in inlet and an outlet on the front andback sides of the housing 916, respectively. The wire aperture extendsthrough a central region of the housing and extends through both a wipercavity 920 and a pad cavity 922 in the housing.

With reference to FIG. 38, the wiper cavity 920 and the pad cavity 922are configured to support a wiper 914 and an absorbent pad 908,respectively. The wiper 914 and the absorbent pad 908 may besubstantially the same as the absorbent pads and wipers shown in FIGS.33 and 34, but are received within the housing 916. The absorbent pads908 and wipers 914 may also include a wire aperture defined therethroughor may include two or more components compressed towards each other bythe housing to define a small gap for the guide wire to extend through.In these configurations, the guide wire 904 is threaded through thelead-in inlet, into the wire aperture 918 of the housing, through a wireaperture of the wiper 914 and the absorbent pad 908 and then out theoutlet to exit the housing 916. In other words, in this configuration,the guide wire 904 is axially loaded into the housing 916.

During operation, the housing 916 is positioned between the patient andthe drive mechanism and the guide wire 904 is threaded into the housing916 as described above. As the guide wire is moved or retracted by thedrive mechanism, the wiper 914 acts to wick fluids and debris from theguide wire 904 and whatever fluids or debris remain on the wiper 914 areabsorbed by the absorbent pad such that as the guide wire 904 exits thehousing 916 the wire may be substantially dry or otherwise clean. Duringprolonged use, the absorbent pad 908 may become saturated and have to bereplaced. In these instances, the guide wire 904 is removed from thehousing 916 and the housing is replaced with a new, non-staturedhousing. The guide wire 904 is then threaded into the new housing 916 asdescribed above and the drying/cleaning process can begin again as thedrive mechanism is activated.

In some embodiments, the debris cleaning mechanism may also include anair based drying or cleaning mechanism. For example, the debris cleaningmechanism may include a heating element, air blower or dryer, and/or avacuum or suction device. FIG. 39 illustrates a side view of an examplea debris cleaning mechanism including a suction device. With referenceto FIG. 39, in this example, the cleaning clamps 1002 of the debriscleaning mechanism 1000 may include the wipers 1014 and optionally mayinclude the absorbent pads (not shown in this embodiment). Additionally,with reference to FIG. 39, the debris cleaning mechanism includes asuction device 1024 positioned at the inlet end of the cleaning clamps1002. The suction device 1024 activates a vacuum or other suctioningmechanism to pull fluids and debris off the guide wire 1004 prior to theguide wire 1004 reaching the wipers 1014. In these embodiments, thesuction device 1024 helps to remove most of the fluid and debris priorto reaching the cleaning clamps 1002. This not only helps to ensure thatmore of the fluids and debris are removed from the guide wire 1004 so itis dry and less prone to slippage, but also helps to extend the life ofthe cleaning clamps 1002. For example, when the absorbent pads 1008 areused, the suction device 1024 reduces the amount of fluids that areabsorbed by each of the pads 1008 by removing the fluids prior toreaching the pads so that the pads may be used for longer periods oftime.

As briefly noted above, in addition to activating a suction mechanism toremove the fluid, the suctioning device may be replaced by a blow-dryingdevice that blows air onto the guide wire 1004 to help remove the fluidand debris and/or evaporate the fluid and debris. Similarly, a heatingelement may be positioned at the entry to the cleaning clamps toevaporate the fluids and help to clean the wire. Also, the suctioningdevice, blowing device, and/or heating element may be used with orwithout the cleaning clamps including the absorbent pads and/or wipers.In other words, the drying mechanism 1000 may include just the suctionmechanism, drying mechanism, and/or heating mechanism.

In many of the embodiments of the debris cleaning mechanism described inFIGS. 30-39, the guide wire is typically moved relative to the absorbentpad. However, in some embodiments, the absorbent pads may also be movedrelative to the guide wire to change the areas of the absorbent pad incontact with the guide wire, increasing absorption and helping to extendthe life of the pad. FIG. 40 is a perspective view of an example of thedebris cleaning mechanism including a movable absorbent pad. Withreference to FIG. 40, in this example, the debris cleaning mechanism1100 may include an absorbent pad that moves in a longitudinal directionD_(L) and optionally in a rotational direction R₁ relative to the guidewire 1104. That is, the absorbent pad 1108 may be rotated and movedhorizontally relative to the guide wire 1104 so that various areas onthe outer surface of the absorbent pad 1108 are brought into contactwith the guide wire 1104, so that the entire absorbent pad is exposedand able to absorb fluids, rather than only one section.

In one embodiment, the absorbent pad may be received into a bracketsimilar to the pad holder 606 of FIG. 32, which may move laterallyacross the guide wire 1104 and the pad 1108 may be a cylindrical shapeand rotate due to the movement of the guide wire 1104 by the drivemechanism. In other embodiments, the absorbent pad 1108 may be connectedto an axel or other support device that extends through a center of thepad 1108 or is otherwise configured to rotate the pad 1108 and also movethe pad in the longitudinal direction D_(L). As the absorbent padbecomes saturated or otherwise needs to be replaced, another pad can beinserted into the pad holders, or may be inserted coaxially to the firstsaturated pad.

It should be noted that any of the features of the drying mechanismsdescribed in FIGS. 30-40 may be used with any of the other features ofthe other embodiments. For example, the wipers may be combined with thedrying mechanism of FIG. 40. As another example, the absorbent pads maybe used with the suction mechanism of FIG. 39, instead or in addition tothe wipers. As such, the description of any particular implementation ismeant as illustrative only and many other embodiments andimplementations are envisioned.

Controlling Active Drive Systems Synchronizing and Aligning Active DriveMotors

To optimize the continuous effective insertion of an elongate memberwith the mechanisms described above, the angular position of theinsertion and grip motors' output shafts generally must be synchronizedso the mechanism is inserting when the dynamic gripper is closed and thestatic grippers are open. Subsequently, it is necessary to have thedynamic gripper open when the insertion motor is moving backwards beforethe dynamic gripper re-clutches on the elongate member to move theelongate member forward again via the insertion motor. Without propersynchronization between the insertion and grip motors, however,insertion becomes less effective. For instance, if the dynamic gripperis closed when moving backwards or for even part of the backward stroke,then the elongate member would retract rather than insert. Hence, theefficiency of the mechanism is reduced with regards to the effectiveinsertion rate.

Accordingly, precisely determining the location of a motor in themechanisms range of motion is crucial for alignment of multiple motorsand ultimately synchronization of the motors. It is important todetermine the electrical current profile of the mechanism to ascertaindistinctive characteristics, for example peaks and troughs, of thecurrent profile. The distinctive characteristics may occur, for example,due to the presence of varying torque due to cams as the motor in themechanism moves through their range of motion. The motors may be coupledto electrical current sensors, wherein the sensors may be incommunication with a monitor including a processing system, foranalyzing an electrical current profile of each motor.

The electrical current profile, and consequently the peaks and/ortroughs representing distinctive characteristics, may be generated bydriving each motor a full repetition through the motor's range ofmotion. Additionally or alternatively, each motor may be driven multiplerepetitions to compensate for phase shifts of the current signal toyield multiple current profiles, for example to account for latency withthe monitoring system. These electrical current profiles may then beaveraged to compensate for any phase shifts and produce demonstrativecurrent characteristics.

The distinctive characteristics of the current profile may correspond toparticular actions or functions of the motor. For example, FIGS. 41 and42 illustrate exemplary distinctive characteristics for the currentprofile of the insert and grip motors, respectively. In the exampleaccording to FIG. 41, the peaks in the current profile may represent the“forward” and “backward” strokes of the dynamic gripper (e.g., via theinsert motor). For instance, the first peak 1200 in current may indicatethe start of the backwards motion and the second peak 1202 may indicatethe start of forward motion. In an alternative implementation, the firstpeak 1200 may represent clockwise rotation around an axis, whereas thesecond peak 1202 may indicate counterclockwise rotation. The action ofthe motor is inconsequential as the disclosure is not limited to anyparticular type of mechanism. For example, while some embodiments may begenerally directed to rotational mechanisms or motors, other types suchas translational mechanisms may also be employed.

For example, FIG. 42 illustrates distinctive characteristics indicatedby both peaks and troughs. For instance, the first or intermediate peak1204 in current may indicate that the static (or outer) grippers areopening while the first or intermediate trough 1206 may indicate thestatic grippers are closing. On the other hand, the current of thegripper motor may be at its maximum, for example at its highest peak1208, when the gripper is opening and at its minimum or lowest trough1210 when the dynamic gripper is closing.

The filtered electrical current profile may be used to locate orpinpoint where exactly in the range of motion each motor is in at agiven time. The distinct characteristics of each motor's electricalcurrent profile, for example the relevant peaks and/or troughs, mayindicate the motor's position in response to a given motor's range ofmotion. Such current peaks and/or troughs or other characteristics maycorrespond to loading or unloading of an electrical drive system andassociated electrical current(s). For instance, with reference to FIG.41, the second peak may represent the commencement of motor insertion.If the exemplary mechanism includes a range of motion for the insertmotor of 7 mm forwards and backwards, the electrical current profileaccording to FIG. 41 signifies that the insert motor begins movingbackwards or retracts 7 mm at the first peak and commences movingforwards or inserts 7 mm at the second peak. Likewise, after analyzingthe electrical current profile for the gripper motor according to FIG.42, the start of the static and dynamic grippers clutching andun-clutching of the elongate member can be precisely determined.Accordingly, the distinctive characteristics correlating to motoractions of the insert and grip motors may be used to align the motorsangular positions for the most effective insertion rate.

The distinctive characteristics of the insert motor may be coordinatedwith complementary distinctive characteristics of the gripper motor tooptimize the efficiency of the mechanism (e.g., optimize maximuminsertion rate). For example, for maximum effective insertion rate ofthe above mechanism, it is necessary to align the closing of the dynamicgripper with the forward motion of the insert motor. With reference tothe electrical current profiles of the respective motors, the positionof the insert motor when the current is at its maximum (e.g., the secondpeak 1202 according to FIG. 41) is aligned with the position of thegripper motor when the current is at the minimum (e.g., the lowesttrough 1210 in FIG. 42). Coordinating the peaks and troughs of theelectrical current profiles with corresponding positions of the motorsensures that the elongate member is ultimately driven by the mechanismmonotonically.

To align the motors, the positional relationship of the motors as themotors progress through their range of motion in the mechanism needs tobe calibrated. The positional relationship may depend on the mechanismused. For instance, the positional relationship for an active drivesystem may use a 1:1 relationship between the insert and grip motors.For proper alignment, an offset may be incorporated into the positionalrelationship determination, and added to the position of one of themotors. The offset may take into account the positional relationshipbetween the motors for a given mechanism (e.g., 1:1 ratio, 2:1 ratio,3:2 ratio, etc.). Thus, for example, if insert motor X had a peakcurrent indicating insertion motion at 1 rad, and gripper motor Y had aminimum current indicating closing of dynamic gripper at 1.3 rad, thenthe calculated offset would be 0.3 radians. Accordingly, an equationused to calculate the position of motor Y in relationship to motor X is:

pos_(y)=pos_(x)+offset

The points at which the positional relationship between the two motorsis measured may be any position in which a characteristic of the currentprofile for motor Y is aligned with a complementary characteristic inthe current profile for motor X. For instance, the first peak of FIG. 42indicating backwards movement of the insert motor may be aligned withthe maximum current (e.g., the second peak) of FIG. 41 indicating thedynamic gripper is open.

Once the positional relationship is determined, the motors may bemechanically timed as they progress through a full cycle and repeatthrough their range of motion in the mechanism. That is, the mechanismis mechanically timed such that at the same motor speed the insertionmovements of insert motor X and grip movements of gripper motor Ycomplement one another. Accordingly, for every repetition/revolution ofthe insert and grip motor of the active drive mechanism shown in FIGS.2A-21, the complementary actions of each motor are coordinated asfollows:

Revolution Insert Motor X Grip Motor Y  0-¼ Insert 7 mm Dynamic GripperClosed ¼-½ Wait Dynamic and Static Gripper Switch State ½-¾ Retract 7 mmDynamic Gripper Open ¾-1  Wait Dynamic and Static Gripper Switch State

After alignment, motor X and motor Y may be driven at the samevelocities, ensuring that motors will maintain their positionalrelationship. In the example above, insert motor X may be driven at thesame velocity as grip motor Y such that motor Y will always be 0.3 radahead of motor X, thereby ensuring synchronization between the motors.This can be seen in FIGS. 43A and 43B, which provides a graphicalrepresentation of the above table. FIGS. 43A and 43B illustrate theinsert and gripper motor positions during one revolution or one fullcycle/repetition through the mechanism after alignment via thepositional relationship equation above. That is, FIGS. 43A and 43B showthe insert motor synchronized with the gripper motor after alignmentusing each motors filtered electrical current profile.

FIG. 43A illustrates the positions of the gripper motor while FIG. 43Billustrates the movement of the insert motor as they progress throughtheir range of motion per revolution after the motors have beenmechanically timed (e.g., after synchronization). For the first quarterrevolution, the dynamic grippers are closed while the static grippersare open when the insert motor is moving forward or inserting. For thesecond quarter revolution, the dynamic and static grippers switchpositions (e.g., dynamic grippers open and static grippers close) whilethe insert motor stays idle (e.g., neither inserts nor retracts). Thethird quarter revolution of the motors includes the static grippersclosed and the dynamic grippers open as the insert motor moves backwardsor retracts. For the final quarter revolution, the dynamic and staticgrippers switch states (e.g., dynamic gripper closes and static gripperopens) and the insert motor waits and is idle. Thus, upon one fullrevolution, the insert and grip motors are back in the original positionready to re-clutch and insert the elongate member.

FIG. 44 illustrates an exemplary process 1215 for aligning andsynchronizing objects, such as motors, based on electrical currentprofiles. The process 1215 may begin at block 1220, where the electricalcurrent profile for each motor in the mechanism is produced. Theelectrical current profiles may be generated by driving each motor onefull revolution or repetition as its current is filtered and tracked,for example via electrical current sensors. Additionally, the motors maybe driven multiple repetitions to generate a plurality of symmetricelectrical current profiles, and taking the average current profile tocompensate for any phase shifts of the current signal. Once theelectrical current profile is produced, the process may proceed to block1225.

At block 1225, the electrical current profile for each motor is analyzedfor relevant peaks and/or troughs (e.g., analyzed for distinctcharacteristics). For example, the electrical current profile may becommunicated to a monitor for study and analysis. The filteredelectrical current may then be analyzed to determine the distinctcharacteristics of the profile. For instance, with reference to FIG. 42,the gripper motor may produce two peaks and two troughs per repetition.These distinct characteristics may then be associated with motoractions. For example, by monitoring the gripper motor as it progressesthrough its range of motion, it may be determined that the current is atits maximum when the dynamic grippers open, the current has a smallerdistinctive peak when the static gripper is open, and the current is atits minimum when the dynamic gripper closes. The same analysis andassociation may take place with all the motors in the mechanism, forexample associating the insert motion when the insert motor has amaximum electrical current. The process may then proceed to block 1230.

At block 1230, the electrical current profiles of each motor in themechanism are aligned with one another. The alignment of each motor maydepend on the mechanism design. In the above example, to optimize theeffective insertion rate of the peristaltic active drive mechanism, theclosing of the dynamic gripper of the gripper motor needs to be alignedwith the forward (or backward if retracting the elongate member from thepatient) stroke of the insert motor. In terms of the electrical currentprofiles of each motor, the insert motor when the current is at itsmaximum needs to be aligned with the gripper motor when its current isat its minimum (for maximum effective insertion or forward stroke). Theprocess next proceeds to block 1235.

At block 1235, the position at which point in each motor's range ofmotion is determined for the distinctive characteristics of theelectrical current profiles. These determined positions are then used tocoordinate the gripper and insert motor such that the current profilecharacteristics of the insert motor are aligned with complementarycurrent profile characteristics of the gripper motor. For instance, bymonitoring the motors as they progress through the range of motion itmay be determined that the insert motor has its peak current at 1 radwhile the gripper motors has its minimum current at 1.3 rad.Accordingly, the offset may be calculated to determine the positionalrelationship of the motors for proper alignment. That is, the equationused to calculate the position of motor Y in relationship to motor X is:

pos_(y)=pos_(x)+offset

Thus, if insert motor is X and gripper motor is Y, the offset would be0.3 radians (1.3=1+offset). After alignment, motor X and motor Y aredriven at the same velocities, and motor Y will always be 0.3 rad aheadof motor X. This is true for the mechanism described above, as themechanism used a 1:1 relationship between the insert and grip motors.However, the equation holds true regardless of the mechanism positionalrelationship (e.g., 2:1, 3:1, 3:2, etc.). Upon determining thepositional relationship, the process may proceed to block 1240.

At block 1240, the motors may be synchronized to one another such thatcorrelative motor actions complement one another. That is, the mechanismmay be mechanically timed such that at the same motor speed, theinsertion and grip movements are synchronized with each other. Referringto the above example, this means that the dynamic gripper is closed whenthe insert motor is moving forward (or backwards depending if insertionor retraction is the goal), and the static grippers are closed with thedynamic grippers open when the insert motor is moving backwards toreset. The final synchronized mechanism is illustrated in FIGS. 43A and43B. The information obtained in analyzing, aligning, and synchronizingthe motors via the electrical current profiles may be stored into adatabase for future replication. Accordingly, once the motors arealigned and synchronized for the first time, the insert and grip actionsof the mechanism will be synchronized so that the effectiveinsertion/retraction will always be monotonic thereafter.

Variable Stroke Length of Active Drive Motors

In some embodiments, an active drive system may include dynamic grippersthat are configured to vary their stroke length during insertion of anelongate member. As shown in FIGS. 45-46, dynamic gripper 1300 may beconfigured to vary its stroke length during insertion of an elongatemember 1302. Varying the insertion stroke length on dynamic gripper 1300may optimize speed while simultaneously reducing or preventing buckling.At higher insertion forces, short strokes may prevent buckling ofelongate member 1302, and at low insertion forces, longer stroke lengthsmay lead to faster insertion speeds. Retraction may be performed with alonger stroke for increased speed. Using dynamic grippers 1300 withvariable stroke lengths may reduce or eliminate extra anti-bucklingdevices and may increase insertion speeds and usability.

Variable insertion stroke length may be achieved with any mechanism thatuses a peristaltic motion, for example the active drive systemsdescribed in FIGS. 11-21. The peristaltic motion may include advancingelongate member 1302 from a retracted position to an extended positionwith dynamic grippers 1300 (shown as step A), releasing elongate member1302 with outward transverse movement of dynamic grippers 1300 (shown asstep B), retracting dynamic grippers 1300 from the extended position tothe refracted position (shown as step C), and re-gripping elongatemember 1302 by inward transverse movement of dynamic grippers 1300(shown as step D).

FIG. 45 illustrates a longer insertion stroke length during periods oflower insertion forces. In this mode, dynamic grippers 1300 may returnto a fully retracted position before re-gripping and advancing elongatemember 1302. By utilizing this mode, the dynamic grippers 1300 mayoperate at a lower frequency and insert elongate member 1302 at higherspeeds. Also, elongate member 1302 may achieve a higher advancementrate, because the inward spring forces on dynamic grippers 1300 areovercome less frequently and less time may be spent accelerating anddecelerating dynamic grippers 1300. When returning to the fullyretracted position, it may be desirable to retract dynamic grippers 1300as fast as possible with a longer stroke length to accomplish higherspeeds for better usability.

Alternatively, FIG. 46 illustrates a shorter insertion stroke lengthduring periods of higher insertion forces. For example, dynamic grippers1300 may return to an intermediary retracted position before re-grippingand advancing elongate member 1302. By utilizing this mode, buckling ofthe elongate member may be reduced or avoided with a lower advancementrate. Reducing the insertion stroke length to the intermediary retractedposition may reduce anti-buckling equipment, cost, setup time, andpotential damage to elongate member 1302.

Stroke length may vary based on insertion forces and therefore it may beuseful to detect insertion forces or predict buckling in order tooptimize the stroke length. Force sensors may measure insertion forces,for example, to help anticipate and detect buckling. Test data on avariety of elongate members with varying characteristics may determinethe force thresholds used to determine the buckling forces.Characteristics may include the diameter, stiffness, or material ofelongate member 1302.

The system may recognize, using force sensors, when the insertion forceson elongate member 1302 reach upper and lower force thresholds. Theupper force threshold (i.e. for a buckling condition) and lower forcethreshold (i.e. for a baseline condition) may be derived from empiricaldata and specified given the particular type of elongate member 1302 andthe current unsupported length or stroke length.

When the insertion forces on elongate member 1302 reach the specifiedhigher force threshold, the system may detect or indicate to theoperator and/or operator workstation that buckling may potentially occurand the stroke length may be automatically or manually shortened inreal-time to reduce or avoid potential buckling of elongate member 1302.Alternatively, when insertion forces reach a lower force threshold, thestroke length may be lengthened in real-time to increase insertionspeed. Force sensors may be utilized to change the stroke length ofdynamic grippers 1300 to optimize speed and buckling reduction inelongate member 1302.

Optical sensor 1304 may be utilized to confirm if elongate member 1302is in a baseline condition, as shown in FIG. 47, or a bucklingcondition, as shown in FIG. 48. An elongate member may be insertedthrough valve 1306, for example a hemostatic valve. Optical sensor 1304may detect if elongate member 1302 is inside or outside its field ofview. The system may detect or indicate to the operator and/or operatorworkstation that buckling has occurred. Multiple optical sensors 1304may be oriented in a vertical row perpendicular to elongate member 1302to determine the severity of buckling or in a horizontal row alongelongate member 1302 to detect the location or length of buckling. Byhaving optical sensors 1304 oriented in rows, the area of detection forbuckling increases and the height or length of the buckling may bedetermined. The higher or longer the buckling, the more severely thebuckling will impede insertion. Optical sensors 1304 may also beutilized to adjust the stroke length of dynamic grippers 1300.

In some embodiments, optical sensors 1304 may be used in conjunctionwith force sensors. Using force models to set the upper and lower forcethresholds, real-time force data may be compared to the force models todetermine when buckling may occur. By comparing real-time data withmodel data, the system may detect or predict a buckling condition to theoperator and/or operator workstation. Upon prediction of a bucklingcondition, the stroke length of grippers 1300 may be automaticallyadjusted or manually adjusted by controls on the operator workstation toprevent buckling. Alternatively, upon a prediction of buckling, dynamicgrippers 1300 may be re-clutched forward to shorten the stroke lengththereby reducing the stroke length and the insertion speed of elongatemember 1302. If the system cannot predict buckling in time and takeprecautionary measures as described above, and if buckling actuallyoccurs, then the operator workstation may indicate a warning to the userthat buckling has occurred, so the user may take corrective actions suchas checking elongate member 1302 for damage or kinks Any combination offorce sensors, optical sensors 1304, and empirical models may beutilized to re-clutch dynamic grippers 1300, for example, to reduce thestroke length to help prevent buckling of and damage to elongate member1302.

Dynamic grippers 1300 may also re-clutch elongate member 1302 whenswitching between retraction and insertion modes. A transition fromretraction to insertion could constitute a forward re-clutch of dynamicgrippers 1300 to revert to a longer stroke length during retraction. Forthis transition, the possibility of buckling should be determined asdescribed above and the insertion stroke length should be adjustedappropriately.

Due to the variability in elongate members 1302, the characteristics ofeach type of elongate member 1302 may be helpful in determining theforce thresholds for buckling detection and prevention. Theconfiguration of the system may depend on the type of elongate member1302. The type of elongate member 1302 may be specified by user input,automatically determined by a sensor, or a combination thereof. Anoptical sensor, for example, may determine the diameter of elongatemember 1302 and the user may input material characteristics. Materialcharacteristics may include material and coating types, for examplepresence of a hydrophilic coating. With the information on the type ofelongate member 1302, the system may automatically or the user maymanually specify the force thresholds for the particular type ofelongate member 1302. With reference to FIG. 49, additional instrumentsmay assist with the detection and prevention of buckling. The system1310 may include a real-time imaging device 1312, for examplefluoroscopy. With an imaging device 1312, the user can see when they areinserting in an area likely to require higher insertion forces, forexample, due to tortuous anatomy or anatomical obstacles. The user mayuse visual feedback from the imaging device 1312 to determine insertionforces. The user may vary a haptic input to vary the stroke length ofdynamic grippers 1300. The user would have to deduce the amount ofrelative force being applied to the elongate member based on visualfeedback and adjust the stroke length accordingly.

The system 1310 may also include a haptic device that mimics user motionand provides tactile feedback to the user. The haptic device may mimicthe motions of and forces applied by the user. The haptic device maydirectly translate the user's motion to vary the stroke length to anadjustment in stroke length by dynamic gripper 1300.

Managing Elongate Member Slip

During use of the active drive systems described above, it is importantto accurately position the elongate member in the patient and to retainthe elongate member at that position until a desired task isaccomplished. However, elongate members are preferably designed andmanufactured to facilitate insertion into the patient without undueresistance, and elongate members may slip, migrate, or otherwise movewith respect to the patient so that the tip of the elongate member movesaway from the desired position. Thus, there exists a need to predict andreduce slip of an elongate member.

FIG. 50A illustrates one embodiment of a catheter assembly 1400comprising a slip detection system including one or more sensors fordetecting slip of an elongate member. As shown in FIG. 50A, the catheterassembly 1400 may include an elongate member 1402, a first sensor 1404,and a second sensor 1406. As further described below, a drive mechanism1408 and splayer 1410 may be provided for driving insertion/retractionof the elongate member 1402, and steering the elongate member 1402,respectively. The elongate member 1402 may be of any size, and may havea proximal portion 1412 and a distal portion 1414. The first sensor 1404is located adjacent the distal portion 1414 of the elongate member 1402and may be configured to measure a displacement ΔY of the distal portion1414 of the elongate member 1402. The second sensor 1406 is locatedadjacent the proximal portion 1412 of the elongate member 1402 and maybe configured to measure a displacement ΔW of the proximal portion 1412of the elongate member 1402.

The drive mechanism 1408 may be configured to translate the elongatemember 1402 along a commanded insertion distance ΔX. Any drive mechanismmay be employed to command translational and/or rotational motion of theelongate member 1402, including but not limited to grippers, rollers, orthe like as described above.

In some embodiments, the first sensor and/or the second sensor may beoptical sensors or roller sensors (i.e., contact sensors), for example.More specifically, optical sensors may be used to read a translationalposition of the elongate member 1402, for example the proximal portion1412 (represented as Y in the Figures) and/or the distal portion 1414(represented as W in the Figures). Optical sensors may advantageouslyallow placement of the sensors outside a sterile barrier enclosing theelongate member 1402. In some embodiments, a contact sensor may includea roller or wheel in contact with the elongate member 1402 or portionsthereof, and may measure a displacement or translational motion of theelongate member 1402 by passively rolling in response to motion of theelongate member 1402. In contrast to optical sensors, a contact sensormay require placement within the sterile field that includes theelongate member 1402, since it generally remains in contact with theelongate member 1402 during operation.

In some embodiments, any number of additional sensors may be at anylocation along the elongate member 1402 and/or on the drive mechanism1408 for measuring any additional conditions of the elongate member 1402that may be desired. For example, the drive mechanism 1408 and/orsplayer 1410 may measure an insertion force applied to the elongatemember, an insertion speed of the elongate member 1402, or a grip forceapplied to the elongate member 1402 by the drive mechanism 1408.Alternatively or additionally, separate sensors (not shown) may beprovided for detecting insertion force applied to the elongate member1402 or any portion thereof.

FIG. 51 illustrates an exemplary process 1420 for slip and bucklingdetection and correction. Process 1420 may begin at block 1425 where auser may position or set up a catheter assembly 1400. More specifically,as described above an elongate member 1402 having a proximal portion1412 and a distal portion 1414 may be provided. Additionally, a firstsensor 1404 configured to measure a proximal displacement ΔY of theelongate member 1402, a second sensor 1406 configured to measure adistal displacement ΔW of the elongate member 1402 and a drive mechanism1408 configured to translate the elongate member 1402 along a commandedinsertion distance ΔX may be provided.

Proceeding to block 1430, the user may set or input a type and/or sizeof the elongate member 1402 into the system. For example, a diameter ofthe elongate member 1402 or material associated with the elongate member1402 may be input. As will be described further below, these inputs maybe used to determine a slip and/or buckling condition of the elongatemember 1402. Process 1420 may then proceed to block 1435.

At block 1435, a predetermined initial setting(s) for the drivemechanism 1408 may be set or input by the user or may be automaticallyloaded by the system based on a logged value, for example from aprevious use or test of the elongate member 1402. The predeterminedinitial settings may include: an initial grip force (IGF), a minimumgrip force, a maximum grip force, a minimum insertion force, and amaximum insertion force.

Proceeding to block 1440, the user may command an insertion distance ΔXfor the elongate member 1402.

At block 1445, the drive mechanism 1408 may process the commandedinsertion distance ΔX to drive the elongate member 1402 according to thecommanded insertion distance ΔX.

At block 1450, data may be measured by one or more of the sensors. Thefirst sensor 1404 may measure a proximal displacement ΔY of the elongatemember 1402, and the second sensor 1406 may measure a distaldisplacement ΔW of the elongate member 1402. In addition, any of thesensors may also measure insertion force, and/or insertion speed of theelongate member 1402 and/or grip force of the drive mechanism 1408.

At block 1455, the sensor data may be analyzed or received, for exampleby an application configured to determine a buckling and/or slipcondition of the elongate member 1402. For example, as described furtherbelow, one embodiment of a process for analyzing sensor data may includeanalyzing translational or displacement data from the first and secondsensors 1404, 1406.

In one example, the commanded insertion distance ΔX, the proximaldisplacement ΔY and the distal displacement ΔW are all compared todetermine a buckling and/or slip condition associated with the elongatemember 1402. For example, proceeding to block 1460, a slip and/orbuckling condition associated with the elongate member 1402 may bedetermined or detected using the sensor data discussed above in block1455.

For example, if the commanded insertion distance sent to the drivemechanism 1408, the measured proximal displacement ΔY, and the measureddistal displacement ΔW are all equal, then no slip or buckling conditionis detected. More specifically, when the commanded insertion distance ΔXand displacements ΔY and ΔW of both the proximal and distal portions ofthe elongate member 1402, respectively are equal, then the elongatemember 1402 will generally not have buckled. The lack of buckling isdemonstrated by the equal displacement of the proximal portion 1412 anddistal portion 1414, in this exemplary illustration. Moreover, theelongate member 1402 will also not have slipped with respect to thedrive mechanism 1408 when the commanded distance ΔX provided to thedrive mechanism 1408 is equal to both of the proximal and distal portiondisplacements ΔY and ΔW. More specifically, since the displacement ofthe elongate member 1402 is equal to the commanded movement distance ΔX,no slip between the drive mechanism 1408 and the elongate member 1402 isapparent.

On the other hand, if discrepancies exist between the displacement datameasured by the first and second sensors 1404, 1406 and/or the commandedinsertion distance ΔX, the differences between the sensor data andcommanded distance may indicate the presence of a buckling and/or slipcondition in the elongate member 1402.

For example, if the proximal displacement ΔY is not equal to the distaldisplacement ΔW, as shown in FIG. 50B, this may indicate that theelongate member 1402 has buckled at some point in between the first andsecond sensors 1404, 1406. In one embodiment, buckling may be evidencedby a greater displacement ΔY of the proximal portion 1412 of theelongate member 1402 compared with the displacement ΔW of the distalportion 1414 of the elongate member 1402.

Additionally, if the commanded insertion distance ΔX does not equal theproximal displacement ΔY, this may indicate that the proximal portion1412 of the elongate member 1402 has slipped with respect to the drivemechanism 1408 which is imparting insertion motion to the elongatemember 1402, and accordingly a slip condition is detected.

Proceeding to block 1465, a notification of the slip and/or bucklingcondition(s) may be provided, for example to the user. In someembodiments, a visual or audible notification may be provided.Alternatively or in addition, haptic feedback may be provided via acontrol interface (not shown) of the elongate member 1402. Anynotification may be of various intensities and frequencies and mayinclude any color light, flashing light, sound, visual indicator, ortext-based message on a display. Process 1420 may then proceed to block1470.

At block 1470, the system may take corrective action with respect to anycondition(s) detected in block 1465. Corrective action may be takenautomatically by the system and/or drive mechanism 1408, for examplewithout intervention by the user, or corrective action may be takendirectly by the user to correct the condition, for example uponobserving one of the above-mentioned indicators provided at block 1465.Upon correction of the condition(s), the drive mechanism 1408 may thencontinue to drive the elongate member 1402 for the remainder of thecommanded distance X.

Corrective action may not be needed if, for example, there is no slip orbuckling detected in the elongate member 1402, and a grip force orinsertion force is at a satisfactory value. In cases where no slip orbuckling condition is detected and the grip and insertion forces aresatisfactory, process 1420 may proceed to block 1475.

On the other hand, if a slip or buckling condition is detected, inputsto the elongate member 1402 may be adjusted to provide a correction ofthe detected condition.

For example, if a slip or a partial slip condition is detected, thedrive mechanism 1408 may adjust a grip force on the elongate member 1402by increasing a grip force of the drive mechanism 1408 upon the elongatemember 1402. In some embodiments, grip force may be increased until theslip condition is no longer detected, for example the commandedinsertion distance ΔX is equal to the measured proximal displacement ΔY,including any corrections for reduced translation during the previouslydetected slip condition. Once the measured proximal displacement ΔY isequal to the commanded insertion distance ΔX over a period of time, theslip condition is no longer present for that period of time. Process1420 may proceed to block 1475.

In another example, if a buckling condition is detected, drive mechanism1408 may drive the elongate member 1402 in order to correct the bucklingcondition, for example by slowing or even reversing insertion movementof the elongate member 1402. More specifically, buckling of the elongatemember 1402 may be corrected by moving the proximal portion 1412 of theelongate member 1402 such that it is retracted away from the patientinsertion site, decreasing a difference between the displacement of theproximal portion 1412 ΔY until it is equal or substantially equal to thedisplacement of the distal portion 1414 ΔW.

In some embodiment, other corrections may be provided by the systemand/or drive assembly 1400. For example, a grip force being applied tothe elongate member 1402 may be compared to a predetermined grip forcerange that is desired for the elongate member 1402. If the grip force iswithin the predetermined grip force range, then no correction need bemade and the process 1420 may proceed to block 1475. On the other hand,if a grip force is below a minimum grip force recommended for theelongate member 1402, the grip force applied by the drive mechanism 1408may be increased until the grip force is above the minimum grip force.On the other hand, if the grip force is greater than a maximum gripforce desired for the elongate member 1402, the grip force may bedecreased until it is below the maximum grip force. If a grip force istoo high or too low, system may provide a notification, for example tothe user, of the specific grip force issue. Grip force may be generallyconstantly analyzed to ensure the grip force remains within thepredetermined grip force range.

In some embodiments, insertion force of the elongate member 1402 may beanalyzed and corrected as needed. More specifically, an insertion forceapplied to the elongate member 1402, for example as measured by thedrive mechanism 1408, may be compared to a predetermined insertion forcerange that is desired for the particular elongate member 1402. If theinsertion force is within the predetermined insertion force range, thenthere is no insertion force issue and the process 1420 may proceed toblock 1475.

On the other hand, if the insertion force is less than a minimumpredetermined insertion force setting, this may indicate that theelongate member 1402 is not being inserted at an appropriate speed.Accordingly, an insertion speed of the elongate member 1402 applied bythe drive mechanism 1408 may be increased.

If the insertion force is greater than a maximum predetermined insertionforce setting, the insertion force may be adjusted, for example bydecreasing an insertion speed of the elongate member 1402 or by ceasinginsertion motion of the elongate member 1402. Alternatively oradditionally, if the insertion force is too high, the drive mechanism1408 may automatically adjust a grip force on the elongate member 1402.For example, by reducing a grip force on the elongate member 1402,insertion speed may be reduced by allowing some amount of slip betweenthe elongate member 1402 and the drive mechanism 1408 to occur.Moreover, the system may provide a notification of the specificinsertion force issue. The process 1420 may generally continuouslyanalyze the insertion force to ensure insertion force is within thepredetermined insertion force range or is corrected.

The above-noted corrections for slip and buckling conditions, as well ascorrections to grip force and insertion force may be carried outautomatically by the drive mechanism 1408, for example without requiringintervention by the user. Alternatively, corrections may be appliedmanually by the user, for example in response to notification(s) beingprovided by the system of the relevant condition(s).

Sensor data may also be used to allow the system and/or drive mechanism1408 to “learn” appropriate insertion speed, force, and grip settingsfor a given elongate member 1402. For example, proceeding to block 1475,a measured grip force (or any other settings) associated with non-slip,non-buckling or otherwise satisfactory conditions for a given elongatemember 1402 may be logged as the appropriate default setting for theparticular elongate member 1402. Additionally, any conditions resultingin non-desirable conditions such as excessive slip, buckling, ordeviations in grip force or insertion force outside desired parametersmay be logged to avoid or reduce such conditions in future procedures.The settings may be used in subsequent procedures using elongate member1402, as described above in blocks 1475 through 1470, in order toprovide guidance regarding appropriate settings for the elongate member1402 and any corrections made to the operating parameters describedabove. Moreover, as ideal settings may vary amongst different elongatemembers 1402 having different size diameters or types, the logging andmemory of previous procedures and conditions resulting from variousoperating parameters may allow the system and/or drive mechanism 1408 togenerally learn or modify desired operating parameters continuously fora number of different elongate members 1402, thereby reducing theoccurrence of conditions such as slip or buckling in future procedures.The system may thereby determine appropriate default settings for anumber of different elongate members 1402 having differentconfigurations, diameters, sizes, coatings, types, and/or any otherfeature. Accordingly, in subsequent procedures the system mayautomatically load the default settings, for example grip force, basedon the logged grip force. Process 1420 may then terminate.

Alternatively, in some embodiments, a sensor for slip detection mayinclude one or more force sensors, force-sensing resistors, force-pads,pressure sensors, load cells, displacement sensors, distance sensors,proximity sensors, optical distance sensors, magnetic sensors, opticalencoders, or mechanical switches. FIGS. 52 and 53 illustrate a roboticcatheter assembly 1500 having an active drive device with two componentdevices 1502 a, 1502 b thereof, and an elongate member 1504 disposedbetween the devices 1502 a, 1502 b. The active drive device 1502 a, 1502b may be configured to drive the elongate member 1504 in an axialdirection A for insertion or retraction of the elongate member. Thefirst and second devices 1502 a, 1502 b of the active drive device mayeach generally include similar components. For example, the respectivedevices may include a gripper comprising pads 1506 a, 1506 b (otherwisereferred to as a “surface”) for receiving the elongate member 1504secured in a housing 1508 a, 1508 b defining an interior. The padsurfaces 1506 a, 1506 b may engage the elongate member 1504 via frictionbetween the surface of the pad 1506 a, 1506 b and the surface of theelongate member 1504. The housing 1508 a, 1508 b may include a sterilebarrier 1510 a, 1510 b configured to protect the interior of the housing1508 a, 1508 b, and any components disposed therein, from contaminantsin the external environment. Within the housing 1508 a, 1508 b of eachdevice 1502 a, 1502 b there may have a linear guide 1512 a, 1512 bincluding a guide rail 1514 a, 1514 b and a guide block 1516 a, 1516 baxially slidable relative to the respective guide rail 1514 a, 1514 b.The linear guide 1512 a, 1512 b (e.g., the guide rail 1514 a, 1514 b andguide block 1516 a, 1516 b) have a distal end 1518 a, 1518 b and aproximal end 1520 a, 1520 b. The first and second devices 1502 a, 1502 bmay be coupled to a drive system or mechanism 1522 a, 1522 b operable toprovide the axial motion to insert and/or retract the elongate member1504, as discussed in further detail below. Accordingly, the pads 1506a, 1506 b are axially slidable relative to the drive system mechanism1522 a, 1522 b.

The first device 1502 a may include a sensor A associated with theproximal end 1520 a and a sensor B associated with the distal end 1518a. Likewise, the second device 1502 b may include a sensor D associatedwith the proximal end 1520 b and a sensor C associated with the distalend 1518 b. Sensors A, B, C and D may include a force sensing deviceconfigured to measure a force applied. Additionally or alternatively,the sensors A, B, C, D may include a displacement or distance sensorconfigured to measure the displacement of one or both of the pads 1506a, 1506 b relative to the respective drive mechanism 1522 a, 1522 b.According to another variation, the sensors A, B, C, D may include anysensing component configured to detect a change in relation between thepads 1506 a, 1506 b and the drive mechanism 1522 a, 1522 b, includingbut not limited to proximity sensors, optical distance sensors, magneticsensors, optical encoders, mechanical switches, etc. The sensors A, B,C, D may communicate with the workstation, electronics rack and/orelectronics box via an interface (not shown). The interface(s) may beconfigured to transmit data from the sensors A, B, C, D to theworkstation, electronics rack, and/or electronics box. The interface(s)may be one-directional such that data may only be transmitted in onedirection. Additionally, the interface(s) may be bi-directional, bothreceiving and transmitting data between the sensors A, B, C, D and theworkstation, electronics rack, and/or electronics box.

The respective sensors A, B, C, D may be accommodated within the housing1508 a, 1508 b which may secure the pads 1506 a, 1506 b. The housing1508 a, 1508 b may include a single component or may include a pluralityof components. For instance, the housing 1508 a, 1508 b may include caps1524 a, 1524 b adjacent to the sensors A, B, C, D and an internal shell1526 a, 1526 b for additional protection from the surroundingenvironment. The caps 1524 a, 1524 b may be removed to access thesensors without having to also remove the internal shell 1526 a, 1526 b.The housing 1508 a, 1508 b may secure the sensor B and C in place at thedistal end 1518 a, 1518 b and secure the sensors A and D in place at theproximal end 1520 a, 1520 b.

In the following discussion, reference to the housing 1508 a, 1508 b maybe synonymous with the housing 1508 a, 1508 b, caps 1524 a, 1524 b andinternal shell 1526 a, 1526 b. The first and second device 1502 a, 1502b may include an axial clearance X between at least one of the distalends 1518 a, 1518 b and the respective sensor B, C and/or between atleast one of the proximal ends 1520 a, 1520 b and sensors A, D.According to a non-limiting example, the respective clearances X, X maycomprise a few millimeters or less, e.g., 0.1 mm to 5 mm. The magnitudeof the clearances X, X may depend at least in part on the manufacturingtolerances associated with the assembly 1500 components.

In order to translate the pads 1506 a, 1506 b axially, the drivemechanism 1522 a, 1522 b may actuate one or both of the devices 1502 a,1502 b via a drive post 1528 a, 1528 b. The guide rail 1514 a, 1514 b ofthe linear guide 1512 a, 1512 b may be coupled, fastened, fused, orotherwise adhered to the housing 1508 a, 1508 b, whereas the guide block1516 a, 1516 b may be attached to the drive post 1528 a, 1528 b, whichin turn may be connected to the drive mechanism 1522 a, 1522 b. As such,the guide rail 1514 a, 1514 b may be in slidable communication with theguide block 1516 a, 1516 b. Accordingly, the guide rail 1514 a, 1514 band associated housing 1508 a, 1508 b may be axially slidable relativeto guide block 1516 a, 1516 b and associated drive post 1528 a, 1528 b.Therefore, according to one implementation, the pad 1506 a, 1506 b,housing 1508 a, 1508 b, guide rail 1514 a, 1514 b and associated sensorsA, B, C, D may be axially slidable relative to the guide block 1516 a,1516 b and drive post 1528 a, 1528 b.

According to another example, the pads 1506 a, 1506 b and associatedsensors A, B, C, D may be axially slidable relative to the housing 1508a, 1508 b, which may be coupled to the guide block 1516 a, 1516 b anddrive post 1528 a, 1528 b. That is, the housing 1508 a, 1508 b may becoupled to the drive mechanism 1522 a, 1522 b such that the pads 1506 a,1506 b are axially slidable relative to the housing 1508 a, 1508 b. Theoverall principle operation of the devices 1502 a, 1502 b remainsconstant regardless of the implementation, and therefore for purposes ofexpedience will be described with respect to the housing 1508 a, 1508 band pad 1506 a, 1506 b being axially slidable relative to the drivemechanism 1522 a and 1522 b. However, a skilled artisan would understandthat the same principles apply equally to an axially slidable housing1508 a, 1508 b relative to the pad 1506 a, 1506 b. In other words,slippage may be detected in response to the relative axial movement ofthe pads 1506 a, 1506 b with respect to the drive mechanism 1522 a, 1522b, for example via the housing 1508 a, 1508 b and/or the drive post 1528a, 1528 b.

Additionally, the devices 1502 a, 1502 b may include a bias member 1530,as shown in FIG. 53, operatively attached to the pads 1506 a, 1506 b.The bias member 1530 may include a spring or other mechanism configuredto establish a clearance X, X associated with each pad 1506 a, 1506 b.Additionally or alternatively, the clearance X, X may be established atleast in part due to tolerances associated with the components of eachdevice 1502 a, 1502 b. The bias members 1530 may be configured to enablethe guide blocks 1516 a, 1516 b and drive posts 1528 a, 1528 b and/orhousings 1508 a, 1508 b to slide axially relative to the pads 1506 a,1506 b. The respective bias members 1530 may be connected to therespective guide block/drive post and sensors, the respective guideblock/drive post and housings, or any combination thereof. According toone implementation, each device 1502 a, 1502 b may include at least onebias member 1530 associated with one end of the pads 1506 a, 1506 b, forexample via the respective linear guides 1512 a, 1512 b. For instance,each device 1502 a, 1502 b may include one bias member 1530 disposed onopposite ends of the guide block 1516 a, 1516 b and drive post 1528 a,1528 b. That is, the first device 1502 a may include a bias member 1530associated with the end of the pad 1506 a proximal to the axialdirection, while the second device 1502 b may include a bias member 1530associated with an end of the pad 1506 b distal to the axial directionZ, or vice versa. However, it is contemplated that the respective biasmembers 1530 may also be disposed on the same side of the pads 1506 a,1506 b (e.g., both arranged on an end distal or proximal to the axialdirection A). Pursuant to an example, the first and second device 1502a, 1502 b may include inversely correlated clearances X, X on oppositeends of the respective linear guide 1512 a, 1512 b. For instance, beforeadvancement or initiation of the drive mechanism 1522 a, 1522 b, thedrive post 1528 a and/or housing 1508 a of the first device 1502 a maybe in a distal position and therefore have a proximal clearance X. Onthe other hand, the drive post 1528 b and/or housing 1508 b of thesecond device 1502 b may be in a proximal position and therefore have adistal clearance X. Consequently, converse sensors A and C or B and D offirst and second devices 1502 a, 1502 b, respectively, may detect theforce of the respective bias member 1530 depending on the placement ofsaid bias members 1530 within the device 1502 a, 1502 b. The biasingforce of the bias member 1530 may be less than the driving force of thedrive mechanism 1522 a, 1522 b. On the other hand, the biasing force maybe greater than the resisting force of friction between the pads 1506 a,1506 b and the elongate member 1504.

According to another example, each sensor A, B, C, and D may beassociated with a bias member 1530. The bias members 1530 may beconfigured to center the linear guide 1512 a, 1512 b with respect to thehousing 1508 a, 1508 b, or vice versa, when the respective device 1502a, 1502 b is inactive. Therefore, the respective linear guides 1512 a,1512 b may include an equidistant axial clearance X between the distalend 1518 a, 1518 b and sensors B, C, and between the proximal end 1520a, 1520 b and sensors A, D.

During normal driving conditions, the drive mechanism 1522 a, 1522 b maybe configured to alternate driving each respective device 1502 a, 1502 bsuch that one device is actively advancing the elongate member 1504 andthe other is passively translating along with the elongate member 1504.Additionally or alternatively, the drive mechanism 1522 a, 1522 b maydesignate either the first or second device 1502 a, 1502 b as the activedevice and the other as the passive device. This may be done bymonitoring the initial force on both devices and designating the devicewith the higher force as the active device and designating the devicewith the lower force as the passive device. During insertion orretraction, a driving motion or force is provided by the guide block1516 a and/or 1516 b and drive post 1528 a and/or 1528 b, via the drivemechanism 1522 a and/or 1522 b, as the guide block 1516 a and/or 1516 band drive post 1528 a and/or 1528 b abuts or otherwise communicates withthe sensors A, B, C, D and housing 1508 a, 1508 b.

According to one implementation, the bias member 1530 may exert a forceto displace the guide block 1516 a, 1516 b and drive post 1528 a, 1528 bto the distal position or proximal position to provide a clearance X onthe opposite end thereof. For example, as illustrated in FIG. 52, thefirst device 1502 a may include a bias member 1530 on the proximal end1520 a thereby displacing the guide block 1516 a and drive post 1528 adistally creating clearance X. The second device 1502 b may include abias member 1530 on the distal end 1520 b thereby displacing the guideblock 1516 b and drive post 1528 b proximally creating clearance X.However, a skilled artisan would understand that the placement of thebias member 1530 is discretionary, and the same principles apply with nobias member or with bias members 1530 in alternative positions. As justone example, the bias member 1530 in the first device 1502 a may bearranged between the housing 1508 a, guide block 1516 a, and drive post1528 a distally relative to the axial direction Z, thereby axiallymoving the housing 1508 a proximally and creating a proximal clearanceX. If there are no bias members, a skilled artisan would understand thatthe standard tolerances during build and assembly of the parts willensure that one device will take more of the load. Therefore, thepassive device does not imply that the device is totally passive and isapplying no load during advancement of the elongate member. Instead, theterm passive device is used to refer to the device that has the lowerforce.

The respective sensors A, B, C, D may be configured to detect or measurevarious types of data. For instance, the sensors may be configured todetect data including a load or an advancement force F_(ADV) (e.g.,insertion force or retraction force) exerted via the drive post 1528 a,1528 b, the housing 1508 a, 1508 b, and/or pads 1506 a, 1506 b. That is,the sensors A, B, C and/or D may be operable to detect an increase offorce on the pads 1506 a, 1506 b and thereby detect slippage of theelongate member 1504 relative to the pad 1506 a, 1506 b. Additionally,data may include a bias force exerted via the bias member F_(BIAS).Additionally or alternatively, the sensors A, B, C, D may be configuredto detect or measure the displacement of the guide block 1516 a, 1516 band drive post 1528 a, 1528 b relative to the respective housings 1508a, 1508 b. For instance, the sensors B, C may be configured to measure adisplacement ΔX of the distal end 1518 a, 1518 b, and the sensors A, Dmay be configured to measure a displacement ΔY of the proximal end 1520a, 1520 b. The sensors A, B, C and D may communicate the data to theworkstation, for example, to detect slip and/or determine the likelihoodof slip in response to the data received.

According to one example, the elongate member 1504 may be advancedthrough the active driving of the second device 1502 b and the passivetranslation of the first device 1502 a, or vice versa. That is, thesecond device 1502 b may advance the elongate member 1504 via frictionbetween the pad 1506 b and the elongate member 1504. On the other hand,the first device 1502 a may passively translate with the elongate member1504 via friction between the elongate member 1504 and respective pad1506 a of the first device 1502 a. As such, the second device 1502 b maybe operable to advance the elongate member 1504, while the first device1502 a may be operable to detect slippage of the elongate member 1504. Askilled artisan will appreciate, in light of this disclosure, that theexemplary description is not limited to the described implementations.Rather, the disclosure encompasses modifications or variations of thedisclosed examples. For instance, while the disclosure describes adistal clearance X in the active drive device 1502 b, a skilled artisanwill appreciate that this arrangement may be adjusted and within theguidance of the disclosure.

During operation in direction Z, the axial force of insertion may beprovided by the first device 1502 a via the drive mechanism 1522 a. Asillustrated in FIGS. 52 and 53, the second device 1502 b (e.g. passive)may include a clearance X at the distal end 1518 b during advancement indirection Z in normal condition. The clearance X of the second device1502 b may be initiated via a bias member 1530, for example. The seconddevice 1502 b may passively advance in direction Z with the elongatemember 1504 keeping clearance X during normal condition.

Accordingly, the measured data, e.g., total force (F_(TOT)), duringexemplary operational normal conditions may include: sensor A (F_(A))showing force of approximately zero (F=˜0), sensor D (F_(D)) may show aforce equal to force of bias member (F_(BIAS)); sensor B (F_(B)) mayshow a force of advancement (F_(ADV)) plus the force of bias member 1530(F=F_(BIAS)), and second sensor C (F_(C)) of second device 1502 bapproximately zero force (F=˜O)). That is, the measured parametersinclude: F_(A)=˜0; F_(D)=F_(BIAS); F_(C)=˜0; F_(B)=F_(ADV)+F_(BIAS).Additionally or alternatively, the data may take into account theproximity of the respective clearance X, X via the distance between thesensors and the associated ends of the linear guides 1512. For instance,during normal advancement conditions the clearance X between sensor Aand proximal end 1520 a of the first device 1502 a may correspond to theclearance X between sensor C and distal end 1518 b of the second device1502 b.

If, however, slippage occurs, the reaction force of elongate member 1504may be in the direction opposite the advancement direction Z. The pad1506 b of the passive second device 1502 b in this example maycorrespondingly move in a direction opposite direction Z with theelongate member 1504, e.g., the housing 1508 b and guide block 1516 band pad 1506 b may slide axially relative to the drive mechanism 1522 b.Consequently, the clearance X between distal end 1518 b and sensor Cdecreases, and sensor C may register a force and/or a change indisplacement ΔX of the distal end 1518 b. The detection of force orchange in ΔX by the sensor C of the second device 1502 b may indicateslip conditions. Additionally or alternatively, if the drive mechanismwas moving the wire in the opposite direction, opposite direction Z, theclearance X in the first device 1502 a may decrease as the guide block1516 a and pad 1506 a translate towards the proximal position 1520 a,which may likewise indicate slip conditions. According to oneimplementation, the change of displacement ΔX and ΔY between the normaland slip conditions, e.g., the difference of the clearance X, may betaken into account to estimate the actual position of the elongatemember 1504.

In response to detecting slip conditions, measures may be taken to warnthe operator, mitigate the slip hazard, and/or account for the slip tocorrect the slip condition and, in some circumstances, continue drivingthe elongate member 1504, as will be discussed below. Once the initialslip occurrence is detected, therefore, the first device 1502 a (e.g.,passive device pursuant to the above example) may drive the elongatemember 1504 in conjunction with the second device 1502 b. Accordingly,the system 1500 may achieve more advancing force than if the system 1500were to stop or freeze after the initial slip detection/occurrence.

FIGS. 54 and 55 illustrate a system 1600 for detecting and correctingslip of a device relative to an elongate member. The system 1600 may beassociated with catheter assembly 1500 discussed above, but a2-dimension representation is shown to simplify the explanation of thefunctionality of the slip mechanism. That is, the system 1600 mayrepresent the functionality behind actions of the robotic catheterassembly 1500. Additionally or alternatively, the system 1600 may beutilized separate from the components of the catheter assembly 1500.

Referring to FIGS. 54 and 55, the system 1600 may include a computingdevice having a processor 1602 having a memory 1602 a in communicationwith a catheter assembly or drive apparatus 1606 (hereinafter referredto as a catheter assembly 1606). The processor 1602 may be separatefrom, or included with, at least one of the workstation, electronicsrack and/or bedside electronics box. The processor 1602 may includemodules (not shown) representing the functionality relating toprocessing sensor inputs and rendering commands or outputs to thecatheter assembly to mitigate, correct, and avoid hazardous slipconditions. The processor 1602 may be configured to interact with andupdate the memory 1602 a in response to inputs received from thecatheter assembly 1606 (e.g., via sensors) and/or inputs received fromthe user interface (e.g., via manual inputs from the operator).

The components of the catheter assembly 1606 are illustratedschematically in FIGS. 54 and 55, for purposes of illustrating certainembodiments of the system 1600. According to one example, the catheterassembly 1606 may include an elongate member 1608 disposed between afirst device 1610 and a second device 1612 configured to move in anaxial direction relative to the elongate member 1608. The first device1610 may include a first pad or surface 1614 engaging the elongatemember 1608 and the second device 1612 may include a second pad orsurface 1616 engaging the elongate member 1608. According to thisimplementation, a force sensor, load cell or other mechanism to detect aforce is associated with each side of the respective pads 1616, 1614. Assuch, the assembly 1606 may include sensors A, B, C, and D similar to A,B, C, and D shown earlier. The first device 1610 and second device 1612may be fixed to a housing 1618, 1620. As a result of tolerancesassociated with coupling the sensors between respective pads 1616, 1614and the first and second device 1610, 1612, the first pad 1614 andassociated sensors may not measure a force equal to the second pad 1616and associated sensors. In one embodiment, the pad with the smallestclearance between the pad, sensor and housing may become the drivingpad, and the other pad may measure a lower force relative to the drivingpad. The force sensor associated with the other, non-driving pad may notmeasure the entire force of the elongate member 1608. Rather, thenon-driving pad moves forward due to friction between the pads and theelongate member. Assuming device 1612 has the smallest clearance X, thecatheter assembly 1606 may translate the elongate member 1608 duringnormal operation in a direction of insertion I via actively drivingdevice 1612 and 1610 and the pad 1616 associated with device 1612,whereas the opposite pad 1614 (associated with device 1610) passivelytranslates in the insertion direction I via friction between the pad1616, 1614 and elongate member 1608.

Further, each device 1612, 1610 may include a bias member 1622, 1624arranged on an opposite end of the pad 1616, 1614 relative to each other(e.g., the first device 1610 may include a distal bias member 1624relative to the direction of insertion I, whereas the second device 1612may include a proximal bias member 1622). According to one example, thebias members 1622 and/or 1624 may be a variable force bias member, forexample the biasing force F_(BIAS) of each biasing member 1622, 1624 maybe adjustable. The respective bias members 1622, 1624 may be coupled toan end of the pad 1616, 1614 and an associated housing of the device1612, 1610. Additionally or alternatively, the bias members 1622, 1624may be coupled to the sensor A, B, C, D and the pad 1616, 1614. Beforeinsertion, bias member 1622 may push second pad 1616 proximally leavinga distal clearance X, and bias member 1624 may push first pad 1614distally leaving a proximal clearance Y. Consequently, before insertion,sensors A and C may measure an equal and opposite force F of the biasmember F_(BIAS), while sensors B and D may show little or no force,e.g., F_(A)=F_(BIAS); F_(B)=0; F_(C)=F_(BIAS); F_(D)=0.

According to one example as illustrated in FIG. 54, when driving theelongate member 1608 in the insertion direction I before slip occurs,the first pad 1614 is actively driving the elongate member 1608 whilethe second pad 1616 passively moves in the insertion direction I due tofriction. During insertion, sensor C may be providing (or detecting) theinsertion force F_(INSERT) (e.g., causing a force reading), and sensor Amay still detect F_(BIAS), while sensors B and D measure little or noforce. Accordingly, for instance during insertion without slip, F_(B)=0;F_(A)=F_(BIAS); F_(C)=F_(INSERT)+F_(BIAS); F_(D)=0. According to oneexample, F_(BIAS) may be greater than the friction in the liner guidesupporting the pad 1614 and 1616 to ensure the pads are located incontact with sensor C and A, respectively. However, F_(BIAS) may be lessthan the insertion force under normal use or operation to ensuremovement of pad 1614 if slippage occurs. According to one example, thedistal clearance X is greater than the elasticity of the mechanism underthe insertion forces experienced such that sensor B does not come incontact with pad 1616 during non-slip insertion. That is to say, duringinsertion without slippage, the second pad 1616 substantially maintainsthe clearance X.

The elongate member 1608 exerts a reaction force F_(REACT) back to thepad 1614, opposite the direction of insertion I. Accordingly, while thesecond pad 1616 is moving with the elongate member 1608 in direction I,F_(REACT) from the elongate member 1608 resists the first pad 1614 inthe direction opposite insertion I. If the elongate member 1608 slips,the second pad 1616 may follow the elongate member 1608 in a directionopposite insertion I due to the slip and sensor B may see an increase inforce. For example, the aggregate force includes:F_(C)=F_(INSERT)+F_(BIAS), F_(A)=0; F_(D)=0; F_(B)=F_(INSERT)−F_(BIAS).

After the initial slip is detected, the system 1600 may autonomouslydetect and counter or mitigate the slippage of the elongate member 1608relative to the pad 1616 and/or 1614 in order to continue insertionafter slip is detected. Additionally or alternatively, the system 1600via the controller 1602 may output an alert to warn the user that sliphas been detected and/or mitigated. Further, the controller 1602 mayfreeze out or stop insertion if the detected slip is greater than atolerance or threshold amount (e.g., the clearance Y of sensor D and/orX of sensor B has entirely bottomed out).

According to one example, the mitigation after slip detection mayinvolve pad 1614 and 1616 opening to release the elongate member 1608and then immediately closing again. This may reset the slip detectionmechanism and potentially allow motion to continue.

According to one example, the drive system may be designed with thecapability to increase the clamp force of the pads on the elongatemember. When slip is detected, the slip detection mechanism may be resetas explained above and the clamp force may be increased on the pads andthen insertion of the elongate member may continue

According to another example, when slip is detected, the slip detectionmechanism may be reset as explained above and then the speed ofinsertion may be reduced potentially reducing the likelihood of furtherslip and then insertion of the elongate member may continue

According to a further example, the bias force F_(BIAS) may be increasedonce the point of slip has been detected. As described earlier, theF_(BIAS) should be less than F_(INSERT) or F_(SLIP) to ensure movementof the passive pad when slip occurs. Therefore, F_(BIAS) will usuallystart out with a low force until a point of slip is detected. Once theF_(SLIP) is known, F_(BIAS) may be increased using variable force biasmember, for example an adjustable spring force (not shown). This allowsthe slip detection mechanism to be reset and motion to continue.Accordingly, the adjusted biasing force F_(BIAS) may establish a newthreshold from which slip is detected.

According to one implementation, the processor 1602 may be configured toexecute instructions, e.g., as stored on the memory 1602 a, to estimateslip force, determine various slip conditions representing thelikelihood that slippage will occur, and/or control the catheterassembly 1606 during slip conditions. The processor 1602 may usesimilarities and symmetries inherent in the sensors A, B, C, and D todetermine slippage, mitigate the issue and instruct the operatoraccordingly.

Per the system 1600 discussed above, since sensor C may directly measurethe force applied to the elongate member 1608 by the driving of pad1614, the force at the moment that slip is detected becomes a measuredor estimated force of slip (e.g., F_(SLIP)=F_(C) at moment of slip) forpad 1614 on the member 1608. That is to say, at the time of slip, ifsensor C reads 2N of force, F_(SLIP)=2N, and the processor 1602 mayassign a slip tolerance accordingly. As such, using both pads 1616, 1614to drive the elongate member 1608 should be able to achieveapproximately 4N of force without slip, as both first and second pads1616, 1614 include similar characteristics. The processor 1602 maylikewise associate a slip threshold with F_(TOT), for example 2F_(SLIP),representing a maximum detected measurement until a high probability ofslippage is determined, assuming a uniform friction force along theentire length of the elongate member and the pad. Additionally, thesystem 1600 may use more than one data set to determine the appropriateforce variables, thereby adding to the accuracy of estimating the slip.For instance, the processor 1602 via the sensors A, B, C, D may measureeach time initial slip occurs and average or filter the values.According to some implementations, the values may vary depending on theelongate member 1608. As such, the system 1600 includes the ability tocontinue driving the elongate member 1608 after the initial slip isdetected, thereby allowing the system 1600 to achieve more insertionforce (and elongate member 1608 displacement) than if the system 1600were to stop or freeze upon the initial slip occurrence.

According to this example, the processor 1602 may be configured todetect slip conditions representing a likelihood of slip at the momentin response to the relationship between the total drive force F_(TOT)relative to the slip tolerance F_(SLIP) and the slip threshold2F_(SLIP). For instance, using F_(TOT), measured via the sum of forcesmeasured at sensors C and B (F_(C) and F_(B), respectively), theprocessor 1602 may determine a slip probability or likelihood based oninputs received from the sensors A, B, C, and/or D. Accordingly, theprocessor 1602 may be operable to control the catheter assembly 1606following the initial slip detection (e.g., continue driving theelongate member 1608 after the initial slip occurrence) in a fewexemplary situations:

In a first condition (“Condition I”), the processor 1602 may determineslip is improbable. According to one exemplary approach, Condition I maybe present when the equation F_(TOT)=F_(C)+F_(B)<F_(SLIP) is true. Inthis instance, slip is improbable and may not occur. F_(B) may showlittle force, e.g., F_(BIAS), but in certain transition periods forcemeasurements may slightly spike. The processor 1602 may be configured todetect and ultimately ignore such force spikes, for example by includinga determined force measurement tolerance. In response to detectingforces satisfying the algorithm of Condition I, the processor 1602 maydetermine Condition I applies and continue driving the elongate member1608.

In a second condition (“Condition II”), the processor 1602 may determineslip is unlikely. According to one example, Condition II may bedetermined when the equation F_(SLIP)<F_(TOT)<2F_(SLIP), is true. Morespecifically, both first and second pads 1616, 1614 may be pushing onthe elongate member 1608 at less force than the slip threshold, e.g.,2F_(SLIP). However, the processor 1602 may trigger Condition II as slipis still possible especially as F_(TOT) increases towards the threshold2F_(SLIP). That is, the closer F_(TOT) is to 2F_(SLIP), the more likelyslippage will occur. In Condition II, the catheter assembly 1606 shouldbe able to drive the elongate member 1608 without slippage of pads 1614or 1616. However, as F_(TOT) increases towards 2F_(SLIP), the processor1602 may output an alert or warning message to the user interface or anindication could be shown that there is a potential for slip, butdriving the elongate member 1608 may still continue. Additionally oralternatively, when F_(TOT) approaches the threshold, e.g., 2F_(SLIP) inthis example, the processor 1602 may freeze or stop the catheterassembly 1606 altogether.

In a third condition (“Condition III”), the processor 1602 may determineslip is likely, and driving the elongate member 1608 should be stalled,halted, or otherwise stopped as slip is likely to occur. In oneexemplary illustration, Condition III may be present when the equationF_(TOT)≧2F_(SLIP) (and consequently F_(TOT)>F_(SLIP)), is true. Inresponse to detecting Condition III, suspension or freezing elongatemember 1608 driving may be warranted unless elongate member 1608 slipdoes not pose a safety hazard. Accordingly, the probability of slippagemay be determined based on whether or not the F_(TOT) falls within apredetermined reference point (e.g., Condition I, II, or III). In thisscenario, Condition III, constant friction is assumed. However, in someinstances, friction may be variable, for example, when the wire containswet sections.

Additionally or alternatively, the processor may be configured togenerate a slip score, which indicates the probability or likelihoodthat slip will occur in a progressive manner (e.g., on a scale of 0 to1, with 0 representing unlikely slip and 1 representing highly likelyslip, for example). The processor 1602 may receive input from thesensors A, B, C, and/or D representing force data, and determine thetotal driving force in response to the sensor input, for example viaaggregating the detected force, taking the product, summation, average,non-linear algorithms such as fuzzy logic, etc. The processor 1602 maybe configured to generate a slip score in response to the determinedtotal driving force, and in reference to defined reference points whichmay be stored and/or programmed into the memory 1604 (e.g., slipthreshold, slip tolerance, a baseline or predetermined value associatedwith normal/typical driving conditions, etc.). The processor 1602 maycombine or otherwise analyze the sensor inputs received and compare thedata with a reference point to generate a slip condition. The higher thegenerated slip score, for example, the more likely slip is to occur.Additionally or alternatively, the processor 1602 may be configured toassociate the slip score to slip conditions I, II, or III, and controlthe catheter assembly 1606 in a corresponding way. The processor 1602may likewise be configured to associate the slip score with an outputcommand to mitigate any hazardous slip issue. For instance, a slip scoreof X may be associated with continued insertion, a slip score of Y maybe associated with a warning output to the user interface, and a slipscore of Z may be associated with freezing the catheter assembly 1606.

In response to detecting a possible slip condition, a warning or alertmay be output to the workstation. For instance, a simple warning, forexample, may be presented as a status message on the display oracoustically. Graphical indicators such as those overlaying afluoroscopic image of the elongate member 1608 may blink, change colors,or otherwise draw attention to the fact that slip is detected and/orlikely. Each detected condition may likewise include a separateindicator, e.g., green, yellow and red flashing indicators forConditions I, II, and III, respectively. Similarly, haptic cues, such asvibrating the controller, may likewise be utilized.

The direction of advancement of the elongate member 1608 may also impacthow the system 1600 may react to slip. For example, if the elongatemember 1608 is being retracted from the patient, there may be fewersafety risks involved and hence the system may allow motion to continue.On the other hand, if the system 1600 is being used for insertion, thenthere may be more safety risks and, and accordingly a more cautiousapproach may be chosen by the system 1600, as described above.

Additionally or alternatively, the processor 1602 may be configured tocompare electrical current profiles associated with the respective forcesensors to detect slip and/or determining whether the differencesbetween measured applied forces deviate or exceed a predeterminedtolerance.

For instance, the system 1600 may be configured to detect slippage basedon the known correlation between sensors A and D. That is, the processor1602 may be configured to recognize the symmetries, correlation orproportionality between corresponding sensors A, B, C, D. According toone implementation, for two sensors on the same side of the first andsecond pad 1614, 1616 (e.g., sensors A and D), the sum of the measuredvalues may equal the total insertion force F_(INSERT) (e.g.,F_(A)+F_(D)=F_(INSERT)). If the first and second pads 1614, 1616 areengaged with the elongate member 1608 without slipping, the motions ofthe pads 1614, 1616 and elongate member 1608 may result in similarchanges in measured force for both sensors A and D (F_(A) and F_(D)).Stated alternatively, the difference between the forces of sensors A andD, |F_(A)−F_(D)|, may result in relatively stable readings during normaloperation (e.g., without slip). As illustrated in FIG. 56A, the stablesection 1626 of the graph may indicate conditions without slip. If thedifference between F_(A) and F_(D) includes a change above a predefinedtolerance, for example section 1628, this change in force difference mayindicate slip. Comparing the correlation of |F_(A)−F_(D)| may be usedadditionally or alternatively to the equations for determiningConditions I, II, and III. This lack of correlation between the twoforces, e.g., F_(A) and F_(D), may be detected via various techniques,including using a threshold, filtering, or other numerical technique.

Additionally or alternatively, the system 1600 may be configured withpattern recognition functionality and therefore detect and analyzeelectrical current profile patterns of various sensors A, B, C, and/orD. For instance, the processor 1602 may be configured to detectanomalies or other abnormalities that may be effecting the sensors A, B,C and D, and therefore provide a check for the catheter assembly 1606components. In the exemplary system 1600, with the use of four sensorsA, B, C, D, at any given time, two sensors should be seeing similar orcorrelated force patterns due to symmetry of the system 1600. Forinstance, before slip occurs, sensors A and B may measure opposite forcepatterns, as with sensors C and D. As illustrated in FIG. 56B, however,when slip has occurred, sensors A and D may measure similar patterns.Corresponding to the increase of F_(D), F_(C) may decrease in asymmetrical way. With these predetermined tolerances stored in thememory 1604, for instance, the processor 1602 may detect anomalies insensor data and therefore pinpoint sensors not behaving as expected,which may ultimately lead to larger system or mechanical issues. Inother words, analyzing the expected force patterns (e.g., electricalcurrent profile, force measurement readings, etc.) for each sensor incomparison to each other and checking for anomalies that could ensurethe sensors A, B, C, D and pads 1614, 1616 are working properly.Additionally or alternatively, utilizing force pattern detection and/orsubtraction of forces from sensors on the same pad (e.g., A-B or C-D)allows the system 1600 to account for noise, temperature drift,hysteresis, etc. of the sensors. Similarly, signal filtering may beemployed to enhance the force pattern detection and recognition.

FIGS. 57 and 58 illustrate an alternative embodiment of a slip detectionsystem including a force gauge, linear encoder, or linear potentiometerfor measuring a slip condition of an elongate member. As shown in FIGS.27 and 28, a dynamic gripper 1700 may include a gripper arm 1702configured to move in the axial direction and rotational direction. Thepair of opposing pads 1704 a, 1704 b, referred to hereinafter as dynamicpads, may be fixed to the gripper arm 1702. As explained above, thedynamic pads 1704 a, 1704 b may be configured to engage the elongatemember to enable the dynamic gripper 1700 to grip the elongate member.The dynamic gripper 1700 may also include a pair of passive pads 1706 a,1706 b also configured to engage the elongate member when the dynamicgripper 1700 grips the elongate member. The passive pads 1706 a, 1706 bmay be slidably connected to the gripper arm 1702 via a linear bearing1708, such as a sleeve bearing carriage or a plastic carriage. This mayallow the passive pads 1706 a, 1706 b to be able to engage the elongatemember at substantially the same time as the dynamic pads 1704 a, 1704 band to rotate with the dynamic pads 1704 a, 1704 b, yet move in theaxial direction along the gripper arm 1702 independent of the dynamicpads 1704 a, 1704 b and the gripper arm 1702. The dynamic pads 1704 a,1704 b and the passive pads 1706 a, 1706 b may each have a defined rangeof motion, for example a maximum distance they can travel in the axialdirection, where the range of motion of the dynamic pads 1704 a, 1704 bis the same as that of the dynamic gripper 1700 described above.

While FIGS. 57 and 58 depict the passive pads 1706 a, 1706 b as beingpositioned behind the dynamic pads 1704 a, 1704 b relative to thedirection of axial movement during insertion, it should be appreciatedthat the passive pads 1706 a, 1706 b alternatively may be positioned infront of the dynamic pads 1704 a, 1704 b.

In some embodiments, the dynamic gripper 1700 may further include ameasurement device 1710 configured to measure the distance traveled inthe axial direction by the passive pads 1706 a, 1706 b. The measurementdevice 1710 may be, but is not limited to, a force gauge, as explainedin more detail below, a linear encoder, or a linear potentiometer.Because the passive pads 1706 a, 1706 b move in the axial directionindependently of the dynamic pads 1704 a, 1704 b and the gripper arm1702 as explained above, the measured distance may or may not be thesame as the distance the gripper arm 1702 may be commanded to move(i.e., the commanded distance). If the measured distance is less thanthe commanded distance, this indicates that the dynamic pads 1704 a,1704 b may not be properly engaged with the elongate member and as such,that there may be slip. In such an event, the drive apparatus may beconfigured to generate an alarm or other alert signal to notify anoperator of the system of the slippage. The operator may then stop themovement of the dynamic gripper 1700 such that the operator may re-gripthe elongate member, and/or open the belts and dry the mechanism. Thealarm may alternatively be generated by a computer (not shown) of thesystem in communication with the drive apparatus. Alternatively or inaddition to the generating of the alarm, the drive apparatus mayautomatically stop the movement in the axial direction and/ormechanically compensate for the slippage, for example, by automaticallyincreasing the grip force of the dynamic gripper 1700 on the elongatemember such that no user input may be required.

In one embodiment, as shown in FIG. 57, a spring 1712 may be operativelyattached to the passive pads 1706 a, 1706 b or to the linear bearing1708. The spring 1712 may be fixed at least one end. The spring 1712generally may be configured to enable the passive pads 1706 a, 1706 b tomove in the axial direction with the elongate member when the dynamicgripper 1700 is gripping the elongate member and the gripper arm 1702 ismoving in the axial direction, and to return the passive pads 1706 a,1706 b to an original axial position when the dynamic gripper 1700releases the elongate member. To achieve this, the spring constant ofthe spring 1712 should be low enough to not hinder the axial movement ofthe elongate member, yet have enough stiffness to return the passivepads 1706 a, 1706 b to center against the sources of friction in thesystem. Furthermore, the range of motion of the passive pads 1706 a,1706 b may be approximately twice the range of motion of the dynamicpads 1704 a, 1704 b.

Where the measurement device 1710 is a force gauge, as mentioned above,it may be attached to a fixed end of the spring 1712. The force gaugemay be configured to measure an applied force on the spring 1712 whenthe passive pads 1706 a, 1706 b are moving axially with the elongatemember. The measured force may then be used to calculate the axialdistance traveled by the passive pads 1706 a, 1706 b by a processor (notshown). The processor may be part of the drive apparatus or may be acomputer in communication with the drive apparatus and/or themeasurement device 1710.

In an alternative embodiment, as shown in FIG. 58, a motor 1714, such asa servo motor, may be operatively attached to the passive pads 1706 a,1706 b or to the linear bearing 1708 in lieu of the spring 1712. Themotor 1714 may be attached to the passive pads 1706 a, 1706 b via anydevice configured to translate the rotational movement provided by themotor 1714 into linear movement, such as a rack and pinion. The motor1714 may be configured to enable the passive pads 1706 a, 1706 b to movein the axial direction with the elongate member when the motor 1714 isnot activated, and to return the passive pads 1706 a, 1706 b to anoriginal axial position when the dynamic gripper 1700 releases theelongate member and the motor 1714 is activated. To achieve this, themotor 1714 generally may have low gearing attached to the axis. In thisapproach, the dynamic pads 1704 a, 1704 b and the passive pads 1706 a,1706 b may have approximately the same range of motion.

In some embodiments, the passive pads 1706 a, 1706 b may be instrumentedwith a load cell configured to measure the force on the insertion axis.Then, the passive pads 1706 a, 1706 b may be served to mirror themovement of the dynamic pads 1704 a, 1704 b to save range of motion. Acontrol loop may be wrapped around the load cell, a motor operativelyconnected to the dynamic pads 1704 a, 1704 b, and a rotary encodermounted on the motor. The motor could be small and highly geared, andthe rotary encoder may be configured to take position measurements. Thisapproach may allow for flexibility in the control of the dynamic pads1704 a, 1704 b as they may essentially “float” similar to haptic devicesthat remove the effect of friction, thereby enabling the dynamic pads1704 a, 1704 b to follow the wire motion easily. Furthermore, thepassive pads 1706 a, 1706 b may be floating in front of or behind thedynamic pads 1704 a, 1704 b. When the dynamic pads 1704 a, 1704 b andthe passive pads 1706 a, 1706 b engage the elongate member, the dynamicpads may be driven by the motor and the only force on the passive padsmay be the motion of the elongate member.

Referring now to FIG. 59, a method 1720 for detecting slip of a grip onthe elongate member by the dynamic gripper 1700 is shown. Method 1720begins at block 1725 in which the pair of dynamic pads 1704 a, 1704 band the pair of passive pads 1706 a, 1706 b engage the elongate membersuch that the dynamic gripper 1700 grips the elongate member. At block1730, the gripper arm 1702 is commanded to move a commanded distance inthe axial direction. Because the dynamic pads 1704 a, 1704 b areattached to the gripper arm 1702, as explained above, and are engagedwith the elongate member, the elongate member moves in the axialdirection with the gripper arm 1702. Furthermore, because the passivepads 1706 a, 1706 b are also engaged with the elongate member, thepassive pads 1706 a, 1706 b also move in the axial direction with theelongate member. At block 1735, the measurement device 1710 determines ameasured distance of the passive pads 1706 a, 1706 b in the axialdirection. As explained above, the measurement device 1710 may include,but is not limited to, any one of or combination of a force gauge, alinear encoder, and a linear potentiometer. At block 1740, the measureddistance is compared with the commanded distance. At block 1745, slipbetween the dynamic pads 1704 a, 1704 b and the elongate member isdetected if the measured distance is less than the commanded distance.Method 1720 may end after block 1745.

However, after detecting slip, method 1720 further may includegenerating an alarm or other alert signal to notify the operator of thesystem of the slip condition. As explained above, the operator may thenstop the movement of the drive apparatus such that the operator mayrealign the elongate member, and/or open the belts and dry themechanism. In addition to or in lieu of the generating of the alarm,method 1720 may include automatically stopping the movement in the axialdirection and/or mechanically compensating for the slippage, forexample, by automatically increasing the grip force such that no userinput may be required.

Prior to ending, method 1720 may also include releasing the grip by thedynamic pads 1704 a, 1704 b and the passive pads 1706 a, 1706 b. Thismay first require a static gripper, as described above, to grip theelongate member such that the position of the elongate member is notcompromised. This may be necessary if the dynamic gripper 1700 hasreached the end of its range of motion, but has not yet traveled theentire commanded distance. While the static gripper is gripping theelongate member, the dynamic gripper 1700, and therefore the dynamicpads 1704 a, 1704 b, may be reset to the start of its range of motion.In addition, the passive pads 1706 a, 1706 b likewise may automaticallyreturn to their original axial position. As explained above, this may beaccomplished by the spring 1712, the motor 1714, or any other similardevice or apparatus.

FIG. 60 illustrates an alternative embodiment of a slip detection systemincluding one or more strain gauges for detecting and managing a slipcondition. The slip detection system described below may be employedwith any pad/gripper active drive mechanism described above. Forexample, clamp 1800 may be incorporated into a dynamic gripper, asdescribed above. Accordingly, a dynamic gripper may include clamp 1800,which generally interfaces directly with the elongate member andfacilitates gripping of the elongate member. Alternatively, a grippermay comprise clamp 1800, and may include one or more segments flexiblycoupled together and interposed by strain gauges. Dynamic gripper 1802may comprise a clamp 1800 having a pair of opposing pads 1804 a, 1804 b,respectively.

As shown in FIG. 60, clamp 1800 may comprise a first set of clampsegments 1806 a, 1808 a, 1810 a opposing a second set of clamp segments1806 b, 1808 b, 1810 b, respectively. Each set of clamp segments may beconfigured for axial motion, for example in the direction of the arrowshown in FIG. 60, with respect to the other set of clamp segments.

Pads 1804 a and 1804 b may each comprise a plurality of first padsegments 1812 a, 1814 a, 1816 a and second pad segments 1812 b, 1814 b,1816 b, respectively. Each pad 1804 a, 1804 b may have any number ofsegments, for example two, three (as shown), or more. Each of the padsegments may be configured to move axially with respect to the other padsegments included in the same set. For example, a pad segment may moveaxially with respect to an adjacent pad segment in response to differentfriction conditions between the different pad segments with respect toan elongate member such as a catheter.

First clamp segments 1806 a, 1808 a, 1810 a and second clamp segments1806 b, 1808 b, 1810 b may each be interposed by first strain gauges1818 a, 1818 b and second strain gauges 1820 a, 1820 b, respectively,that are each configured to provide a strain signal. The first straingauges 1818 a, 1818 b and second strain gauges 1820 a, 1820 b mayalternatively be interposed between first pad segments 1812 a, 1814 a,1816 a and second pad segments 1812 b, 1814 b, 1816 b, respectively.Although the first strain gauges 1818 a, 1818 b may be separated fromthe pad segments 1812, 1814, 1816, mounting first stain gauges 1818 a,1818 b between the clamp segments 1806, 1808, 1810 may allow for moreprecise measurement of relative movement between the pad segments 1812,1814, 1816.

Further, in some embodiments, the pad segments 1812, 1814, 1816 may beremovable from the clamp segments 1806, 1808, 1810, and/or may beincorporated into a sterile barrier (e.g. sterile drape) allowing theclamp segments 1806, 1808, 1810 to remain outside a sterile environmentand potentially reducing costs. For example, a drive system as describedabove, may be positioned under a sterile drape, such that the drivesystem remains outside of the sterile field. In some embodiments, padsegments 1812, 1814, 1816 may be positioned in the sterile field on theclamp segments 1806, 1808, 1810 covered by the sterile drape, such thatthe sterile drape provides an interface between the pads and clamps. Insome embodiments, pad segments 1812, 1814, 1816 and clamp segments 1806,1808, 1810 may be positioned in the sterile field, such that the padsegments and clamp segments are replaced after each use. Further, theelongate member may be positioned within the sterile field and notcovered by the sterile drape, such that the sterile drape is positionedon the drive system in a configuration that allows unrestricted movementof the elongate member. Moreover, the sterile drape may be positionedbetween the pad segments 1812, 1814, 1816 and any other portion of thedrive system (e.g., sensors and clamp segments 1806, 1808, 1810), forexample, to insulate the sterile field from any non-sterile portions ofdrive system. In addition, any portions of drive system (e.g., thesterile drape and pad segments 1812, 1814, 1816) may include asterilizable or disposable material, may be packaged in a substantiallysterile condition, and/or may be configured for single patient use.Adjacent clamp and pad segments may each be interposed by a gap to helpisolate each strain signal. Axial motion between adjacent clamp and padsegments may be measured by the interposed strain gauge to determine ifthe elongate member 1822 is slipping with respect to the adjacent clampand pad segments during insertion or retraction.

First strain gauges 1818 a, 1818 b and second strain gauges 1820 a, 1820b may be configured to collect strain data including the differences inaxial force, along the elongate member 1822, to determine when dynamicgripper 1802 is beginning to slip with respect to elongate member 1822.Strain data may be used to determine when to stop the dynamic gripper1802 from driving the elongate member 1822. System may notify the userto service dynamic gripper 1802, for example, by drying the pads 1804 aand 1804 b. Alternatively, system may automatically adjust dynamicgripper 1802 to reduce slip, for example, by increasing the transverseforce applied to grip the elongate member 1822.

First pad segments 1812 a, 1814 a, 1816 a and second pad segments 1812b, 1814 b, and 1816 b may allow dynamic gripper 1802 to compress andexpand axially. By attaching first strain gauges 1818 a, 1818 b andsecond strain gauges 1820 a, 1820 b, the strain data may indicatewhether each of pad segments 1812 a, 1814 a, 1816 a, 1812 b, 1814 b, and1816 b is slipping or substantially maintaining the transverse force onelongate member 1822. Any or all of pad segments 1812 a, 1814 a, 1816 a,1812 b, 1814 b, and 1816 b may have similar or different sizes, shapes,materials, or gripping forces, for example, to increase the differencein grip between the adjacent pads. Each set of pad segments may beconfigured to compress or expand in an axial direction relative to eachother. Also, each set of pad segments may be configured to resistdeflection in the transverse direction, perpendicular to the length ofelongate member 1822, and rotation about the longitudinal axis ofelongate member 1822.

The embodiments herein may provide a more robust design than using forcesensors that measure the overall pad force alone. A strain signal ofstrain data between two or more adjacent pads may have less noise, forexample, because one pad may slip before another pad. This differencemay be further increased by varying the material or transverse force onthe pad segments to ensure one pad segment slips before another padsegment.

To better interpret the behavior of elongate member 1822 in light of thestrain data, it may be beneficial to differentiate strain signalsreflecting a slipping signal indicating slip of elongate member 1822from a gripping signal indicating normal grip with respect to elongatemember 1822. To assist with this, different materials may be utilizedfor selected pad segments. If the material of one pad segment has ahigher friction coefficient, that pad segment may maintain grip relativeto elongate member 1822 better and facilitate a more reliable slipsignal than a pad segment with a lower friction coefficient material.The materials for each pad segment may be selected for the desiredperformance under a given condition. For example, one material may bebetter for imparting rotational movement of the elongate member 1822,particularly where relative vertical motion between opposing pads isused to impart rotational movement, while another material may be betterfor insertion or axial movement. Alternatively, a dampener such as aspring may be utilized on one or more of the pad segments to reduce thegrip, thereby differentiating the strain signals for those pad segments.

Dynamic grippers 1802 may also include one or more sensors, for examplepiezoelectric sensors, to increase the accuracy and robustness of slipdetection. The piezoelectric sensor may provide a signal in response toa pressure change relative to pads 1804 a, 1804 b, for example, due tovibration from slip. One or more piezoelectric sensors may be embeddedinto or mounted on pads 1804 a, 1804 b, clamp 1800, or any other segmentattached to the pads or clamp. As an example, the piezoelectric sensorsmay be mounted on each clamp 1800 and in contact with either or both ofpads 1804 a, 1804 b. Clamp 1800 may be etched to have a groove in amiddle portion of clamp 1800 to receive the piezoelectric sensor, forexample, to limit the grip force experienced by the piezoelectricsensor. An output of the piezoelectric sensor may be utilized inconjunction with the strain data to detect slips in the elongate member1822 relative to grippers 1802.

For example, the piezoelectric sensor may include a polyvinylidenefluoride film (referred to as “PVDF film”). PVDF film is a relativelyflexible, thin film capable of detecting strain velocity includingrelatively small changes in strain. This type of sensor produces avoltage output based on strain velocity to detect a slip condition basedon a threshold output voltage indicating incipient slip. In addition,two or more pad segments may allow detection of slip propagation basedon their relative motion. For example, a slip detected at a leading padmay indicate impending slip on a trailing pad. Using this information,the grip force could be dynamically adjusted to reduce or prevent theslip on the trailing pad from occurring, for example, by reducing theinsertion speed to retain control of elongate member 1822. In addition,embodiments may include ridges to make signal detection more reliable.

As shown in FIG. 61, dynamic gripper 1802 may include a set of opposingpads 1824 a, 1824 b that may be independently operable with respect toopposing pads 1804 a, 1804 b. Pads 1824 a, 1824 b may be a differentsize (e.g. smaller) with a different (e.g. higher) friction coefficientrelative to pads 1804 a, 1804 b. Pads 1824 a, 1824 b may be configuredto independently detect axial or rotational slip with respect toelongate member 1822. Alternatively, pads 1824 a, 1824 b may be segmentsof pads 1804 a, 1804 b, respectively. Strain gauges may be positionedbetween each of pads 1824 a, 1804 a and pads 1824 b, 1804 b. Someembodiments may also include a separate mount that detects forces.

In some embodiments, as shown in FIG. 62, idler wheels 1826 a, 1826 bmay be connected to pads 1804 a, 1804 b, for example for optical slipdetection. Idler wheels 1826 a, 1826 b may have a surface material witha larger friction coefficient, for example, to detect slip in the axialdirection. Idler wheels 1826 a, 1826 b may each include a roller with anencoder that may be coupled to pads 1804 a, 1804 b, respectively. Whilepads 1804 a, 1804 b move with respect to elongate member 1822, idlerwheels 1826 a, 1826 b may roll along elongate member 1822 to measureaxial movement with respect to elongate member 1822. Alternatively,idler wheels 1826, 1826 b may each include a holonomic wheel, forexample, including rollers mounted on the circumference of each wheel atan angle approximately perpendicular to the rotational axis of eachwheel to simultaneously measure axial and rotational movement withrespect to elongate member 1822.

In some embodiments, a slip detection system is incorporated into theactive drive systems disclosed herein. The slip detection system tracksthe motion or movement of the guide wire without utilizing or extractingsubstantial amounts of energy from movement of the guide wire.Additionally, as will be discussed in more detail below, the slipdetection system is configured so that data related to the position ofthe guide wire and its movement is transferred wirelessly to a trackingassembly, allowing a more sterile environment for tracking the guidewire as the encoding device may be hermetically sealed with the activedrive mechanisms.

In one embodiment, the slip detection system includes an encoderassembly and a tracking assembly in wireless communication with theencoder assembly. The encoder assembly includes an idler wheel, atracking wheel, one or more tracking features connected to or defined bythe tracking wheel, a tracking sensor, and a transmitting device. Theidle wheel and the tracking wheel are rotatable wheels driven bymovement of the guide wire and typically have a low coefficient offriction and require little energy from the guide wire in order to berotated.

The tracking features are connected to the tracking wheel and areselected based on the type of characteristics sensed by the trackingsensor. For example, in one embodiment, the tracking sensor is anoptical sensor and the tracking features form optically distinguishableelements on the tracking wheel (e.g., painted elements, reflectiveelements, apertures, or the like). As another example, the trackingsensor may be a magnetic sensor (such as a Hall effect sensor) and thetracking features may be specifically polarized magnetic elements. Thetracking features and the tracking sensor are selected such that littleor no mechanical contact is required between the sensing element and thetracking wheel. This allows the encoding assembly to track the guidewire without the guide wire transmitting some mechanical energy (e.g.,torque) to the encoding assembly, increasing the efficiency of the driveassembly for the guide wire and also helping to reduce the risk ofslippage.

The transmitting device is in communication with the tracking sensor andreceives tracking data corresponding to the position of the guide wirefrom the tracking sensor. The transmitting device then transmits thedata to the tracking assembly. Examples of the transmitting deviceinclude a radio wave transmitter (e.g., Bluetooth, WiFi, or the like),an acoustic transmitter such as a piezo electrical transducer, anoptical transmitter, an inductive coupling, or the like.

The tracking assembly is in wireless communication with the encoderassembly. The tracking assembly includes a computing device and areceiver. The receiver is in wireless communication with the transmitterand is selected based on the type of data transmission used by thetransmitter. For example, in instances where the transmitter is a radiowave transmitter, the receiver is a radio wave receiver. The receiver isconfigured to receive data from the transmitter of the encoder assemblyand provides the data to the computing device. The computing devicereceives data from the receiver, optionally decodes the data, andanalyzes the data to determine whether slippage has occurred, is likelyto occur based on movement of the guide wire, and may provide an alertsuch as an alarm, notification, or the like, to a doctor or systemoperator regarding the state of the guide wire.

In operation, as the guide wire is driven, such as by one of the activedrive mechanisms disclosed herein, the guide wire rotates the trackingwheel and/or idler wheel. As the tracking wheel is rotated, the trackingsensor detects changes in position or movement of the tracking featureson the tracking wheel. The position or guide wire data is transmittedfrom the tracking sensor to the transmitter which then wirelesslytransmits the data to the receiving device of the tracking assembly. Thereceiving device provides the tracking data to the computing device,which in turn determines whether a slip has occurred, the location ofthe guide wire, and/or other positional related information for theguide wire.

Turning back now to the figures, the slip detection assembly will now bediscussed in more detail. FIG. 63 is a perspective view of an example ofthe slip detection assembly. With reference to FIG. 63, the slipdetection assembly 1900 includes an encoding assembly 1902 and atracking assembly 1904, each will be discussed in turn below.

The encoding assembly 1902 is typically housed within a sterilecompartment for the active drive system. For example, the encodingassembly 1902 may be housed within a compartment enclosing the gripperpads and other features of the drive system. As shown in FIG. 63, theencoding assembly 1902 may be separated from the tracking assembly 1904by a barrier wall 1906, where the wall is typically formed as part of ahousing for the drive assembly. The encoding assembly 1902 includes anidler wheel 1908, a tracking wheel 1910, one or more tracking features1912, a tracking sensor 1914, and a communications module 1916.

The tracking wheel 1910 and the idler wheel 1908 are both round shapeddiscs and may have a minimal thickness. The outer edge of both thewheels 1908, 1910 is configured to engage the guide wire 1918 and rotateas the guide wire 1918 is moved. The idler wheel 1908 and the trackingwheel 1910 may be each supported on an axle 1920, 1922 or shaft and areconfigured to rotate in a rotation direction R. In many embodiments, theaxle 1920, 1922 for each wheel 1908, 1910 is stationary and the twowheels 1908, 1910 rotate about the axle. In other embodiments, the axle1920, 1922 for each wheel 1908, 1910 or for one of the wheels 1908, 1910rotates and may be driven by a motor other source to power the wheelsindependently of the guide wire.

The tracking features 1912 are defined on or connected to the trackingwheel 1910. For example, the tracking features 1912 may be painted,attached by adhesive, formed via molding, punched out, or attached inmany other manners. The configuration and characteristics of thetracking features 1912 are selected so as to be detectable by thetracking sensor 1914. For example, the tracking features 1912 may bedifferently colored regions on the tracking wheel 1910, magneticelements, holes or other formations in the tracking wheel, or the like.As one specific example, the tracking wheel 1910 may be transparent andthe tracking features may be black lines on the top surface of thetracking wheel 1910. As another example, the tracking wheel 1910 may beopaque and the tracking features 1912 may be tracking apertures definedthrough the tracking wheel 1910. The tracking features 1912 are variedbased on the material, color, texture, or the like, of the trackingwheel 1910 so that the tracking features 1912 can be easily detectableby the tracking sensor 1914, as will be discussed in more detail below.

The tracking sensor 1914 is substantially any type of sensor that candetect changes in location or position of the tracking features 1912without touching, physically engaging, or mechanically connecting to thetracking wheel 1910 and/or tracking features 1912. In particular, thetracking sensor 1914 may be in communication, either optically,magnetically, acoustically, or the like, with the tracking wheel 1910.In some examples the tracking sensor 1914 is an optical sensor (e.g.,light sensor), magnetic sensor (e.g., Hall Effect sensor), and/or anacoustic sensor (e.g., microphone), or the like. As shown in FIG. 63, inone embodiment, the tracking sensor 1914 is shaped as a C-bracket and isin optical communication with both a top and bottom surface of thetracking wheel 1910.

The communication module 1916 is in communication with the trackingsensor 1914 and may include a power source 1924, a circuit board 1926,and a transmitting device 1928. The power source 1924 provides power tothe various components of the encoder assembly and may be any componentable to provide energy to one or more components. For example, the powersource 1924 may be a battery, capacitor, a wireless power transmissionmechanism, or a wired power connection.

The circuit board 1926 is in communication with the tracking sensor 1914and the transmitting device 1928. The circuit board 1926 typicallyincludes the electrical components required for operation of theencoding device. For example, the circuit board 1926 may include one ormore processing elements, memory components, and/or other computingcomponents desired.

The transmitting device 1928 is in communication with the processingelement or other components on the circuit board 1926 and optionally maybe connected to the circuit board. The transmitting device 1928 issubstantially any type of data transmission component, such as, but notlimited to, a radio wave transmitter, an acoustic transmitter (e.g.,piezo electrical transducer, ultrasonic transmitter), opticaltransmitter, inductive coupling, or the like. The transmitting device1928 is configured to wirelessly transmit data from the encodingassembly 1902 to the tracking assembly.

The tracking sensor 1914 is in electrical communication with thecommunications module 1916 so that data can be transmitted from thetracking sensor 1914 to the transmitting device 1928 and so that power,if needed, can be transmitted from the power source 1924 to the trackingsensor 1914.

Each of the components of the encoder assembly 1902, including thetracking sensor 1914, tracking wheel 1910, and communications module1916 are housed within a sterile environment such that they areseparated from the outer environment and the tracking assembly 1904 bythe barrier wall.

With continued reference to FIG. 63, the tracking assembly 1904 will nowbe discussed in more detail. The tracking assembly 1904 includes areceiving device 1930 and optionally a computing device 1932. Thereceiving device 1930 is in communication with the transmitting device1928 and is configured to receive data wirelessly from the transmittingdevice 1928. For example, the receiving device 1930 may be a radio wavereceiver, an optical receiver, a microphone or other sound sensor, orthe like, as should be appreciated, the receiving device 1930 may bemodified to match the data transmission method of the transmittingdevice 1928.

The computing device 1932 may be substantially any type of computer orother computing element, such as, but not limited to, a laptop computer,server, desktop computer, mobile computing device, tablet computer,microcontroller, digital signal processor, or the like. The computingdevice 1932 is configured to receive data from the receiver 1930 anddetermine location and tracking information for the guide wire todetermine if slippage has occurred.

Assembly and operation of the slip detection system 1900 will now bediscussed in more detail. With reference to FIG. 63, the idler wheel1908 and the tracking wheel 1910 are each connected to their respectiveaxles 1920, 1922 and positioned adjacent to each other. The two wheels1908, 1910 may be spaced apart by a distance gap that is substantiallythe same width as the diameter of the guide wire 1918. The guide wire1918 is then threaded between the two wheels 1908, 910 so that it is incontact with a portion of the outer edge of each wheel 1908, 1910.

The tracking sensor 1914 is then positioned to be in communication withthe tracking wheel 1910. For example, as shown in FIG. 63, the trackingsensor 1914 is positioned so that the tracking wheel 1910 is receivedbetween a top and bottom bracket of the tracking sensor 1914 allowingthe tracking sensor 1914 to be in optical communication and/or magneticcommunication with the tracking wheel. The configuration of the trackingsensor 1914 depends on the type of characteristics to be sensed. Forexample, the tracking sensor 1914 may be positioned to view one side orsurface of the tracking wheel 1910, which may be varied based on thesurface including the tracking features.

As discussed above, after the encoding assembly 1902 is arranged orconnected together, the assembly may be positioned within a housing orother enclosure. The enclosure forms the barrier wall 1906 and may behermetically sealed or otherwise define a sterile environment. Withcontinued reference to FIG. 63, the tracking assembly 1904 is positionedon the non-sterile side of the barrier wall 1906 and is arranged toprovide communication between the transmitting device 1928 and thereceiving device 1930 through the barrier wall 1906 without distributingor disrupting the sterile environment.

Operation of the slip detection system 1900 will now be discussed inmore detail. As the guide wire 1918 is inserted and/or retracted by thedrive assembly, the guide wire 1918 exerts a force on the outer edges ofthe idler wheel 1908 and the tracking wheel 1910. This force causes thetwo wheels 1908, 1910 to rotate in the rotation direction R. In someembodiments, the idler wheel 1908 and the tracking wheel 1910 may rotatein opposite directions from each other, i.e., clockwise and counterclockwise, respectively. The rotation direction may be determined by theorientation of the guide wire 1918 relative to the wheel. As notedabove, in some embodiments, one or both of the idler wheel 1908 ortracking wheel 1910 may be driven by a source other than the guide wire.For example, one or both of the wheels may assist inretracting/inserting the guide wire.

As the tracking wheel 1910 rotates with movement of the guide wire 1918,the tracking features 1912 move correspondingly. As the trackingfeatures 1912 are connected to the tracking wheel 1910, they will rotatewith the tracking wheel 1910 and vary their location relative to thetracking sensor 1914. As the tracking features 1912 move or changeposition relative to the tracking sensor 1914, the tracking sensor 1914detects the change in position of the tracking features 1912. Forexample, each tracking feature may correspond to a particular locationon the tracking wheel 1910 so as the tracking sensor 1914 detects aparticular tracking feature 1912 the orientation of the tracking wheel1910 relative to the sensing location can be determined. As anotherexample, the tracking sensor 1914 can detect the number of trackingfeatures 1912 and the rate they are passing by or through the sensor1914 and this information can be used to determine data related to theguide wire. In other words, the data corresponding to the trackingfeatures 1912 detected by the tracking sensor 1914 is the guide wiredata as it provides information related to the movement characteristicsof the guide wire.

As the tracking sensor 1914 detects the change in position and/or speedof the tracking wheel 1910 via the tracking features 1912, the trackingsensor 1914 provides the guide wire data to the circuit board 1926 whichthen provides the guide wire data to the transmitting device 1928. Thetransmitting device 1928 then transmits the guide wire data wirelesslythrough the barrier wall to the tracking assembly 1904. The receivingdevice 1930 of the tracking assembly 1904 receives the data andoptionally may transmit the data to the computing device 1932. Thecomputing device 1932 analyzes the guide wire data and may provide anoutput (e.g., alert, stopping the drive assembly, notification, or thelike). For example, if the computing device determines that the guidewire 1918 is moving slower than desired, has not moved as far asdesired, or another deviation from a predetermined threshold, thecomputing device 1932 will determine that a slip has occurred andprovide the desired output. In other words, the receiving device 1930and/or computing device 1932 act to decode the guide wire data andanalyze the guide wire data to determine if a slip or other event hasoccurred.

Using the slip detection system 1900 of FIG. 63, the location, movement,speed, and other characteristics of the guide wire 1918 can be detectedduring a procedure, such as insertion or retraction. The slip detectionsystem 1900 can be configured to provide alerts or other outputs inresponse to a deviation from a desired function. This helps to alertdoctors and other health care workers substantially instantaneously whena slip occurs, allowing the slip to be mitigated as soon as possible.Additionally, because the slip detection system 1900 uses an encoderassembly 1902 that consumes very little energy from the guide wire 1918,operation of the drive assembly is not substantially affected by theslip detection features, as compared to conventional tracking techniquesthat use substantial amounts of torque to activate the encoder. Finally,because the slip detection system 1900 transmits the guide wire datawirelessly, the tracking assembly 1904 can be located outside of thesterile location or housing, allowing the encoding assembly to be tohermetically encapsulated for sterilization purposes, where the decodingand other computing intensive functions can be done outside thesterilized environment.

The systems and methods of the preferred embodiment and variationsthereof can be embodied and/or implemented at least in part as a machineconfigured to receive a computer-readable medium storingcomputer-readable instructions. The instructions are preferably executedby computer-executable components preferably integrated with the systemsand one or more portions of the processor, controller, or workstation.The computer-readable medium can be stored on any suitablecomputer-readable media such as RAMs, ROMs, flash memory, EEPROMs,optical devices (e.g., CD or DVD), hard drives, floppy drives, or anysuitable device. The computer-executable component is preferably ageneral or application-specific processor, but any suitable dedicatedhardware or hardware/firmware combination can alternatively oradditionally execute the instructions.

As used herein, the term “comprising” or “comprises” is intended to meanthat the devices, systems, and methods include the recited elements, andmay additionally include any other elements. “Consisting essentially of”shall mean that the devices, systems, and methods include the recitedelements and exclude other elements of essential significance to thecombination for the stated purpose. Thus, a device or method consistingessentially of the elements as defined herein would not exclude othermaterials, features, or steps that do not materially affect the basicand novel characteristic(s) of the claimed invention. “Consisting of”shall mean that the devices, systems, and methods include the recitedelements and exclude anything more than a trivial or inconsequentialelement or step. Embodiments defined by each of these transitional termsare within the scope of this disclosure.

The examples and illustrations included herein show, by way ofillustration and not of limitation, specific embodiments in which thesubject matter may be practiced. Other embodiments may be utilized andderived therefrom, such that structural and logical substitutions andchanges may be made without departing from the scope of this disclosure.Such embodiments of the inventive subject matter may be referred toherein individually or collectively by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any single invention or inventive concept, if more thanone is in fact disclosed. Thus, although specific embodiments have beenillustrated and described herein, any arrangement calculated to achievethe same purpose may be substituted for the specific embodiments shown.This disclosure is intended to cover any and all adaptations orvariations of various embodiments. Combinations of the aboveembodiments, and other embodiments not specifically described herein,will be apparent to those of skill in the art upon reviewing the abovedescription.

What is claimed is:
 1. A drive assembly, comprising: a first surface anda second surface for engaging an elongate member, the first and secondsurfaces attached to a drive mechanism to move the elongate member; thefirst surface being slidable relative to the drive mechanism and havinga clearance between the drive mechanism and an end of the first surfaceduring movement of the elongate member in a non-slip condition; and asensor associated with the first surface, wherein the sensor isconfigured to detect movement of the first surface in a slip condition.2. The drive assembly of claim 1, further comprising a bias memberoperatively coupled to the first surface to establish the clearance fromthe drive mechanism.
 3. The drive assembly of claim 2, wherein the biasmember includes a force less than a force to move the elongate member.4. The drive assembly of claim 1, wherein each of the first and secondsurfaces are slidable relative to drive mechanism, the second surfaceincluding a second sensor configured to measure a force.
 5. The driveassembly of claim 4, wherein (i) the first surface includes a firstclearance between a proximal end of the first surface and the drivemechanism during movement of the elongate member distally in thenon-slip condition, the first sensor positioned to detect movement ofthe first surface in the slip condition, and (ii) the second surfaceincludes a second clearance between a distal end and the drive mechanismduring movement of the elongate member proximally in the non-slipcondition, the second sensor positioned to detect movement of the secondsurface in the slip condition.
 6. The drive assembly of claim 5, whereineach of the first and second surface includes a bias member to establishthe associated clearance between the respective surface and drivemechanism.
 7. The drive assembly of claim 6, wherein the first biasmember is positioned at the proximal end of the first surface tomaintain the first clearance in the non-slip condition when the elongatemember is moving distally, and the second bias member is positioned atthe distal end of the second surface to maintain the second clearance inthe non-slip condition when the elongate member is moving proximally. 8.The drive assembly of claim 7, wherein the first sensor detects slippageof the elongate member when being moved in the distal direction, and thesecond sensor detects slippage of the elongate member when being movedin the proximal direction.
 9. The drive assembly of claim 8, whereineach of the first and second surfaces includes two sensors, one sensorconfigured to measure axial force applied to the elongate member and theother sensor configured to detect slippage.
 10. A drive system for anelongate member, comprising: an active drive device including: a firstsurface and a second surface arranged on an active drive mechanism forengaging an elongate member; the first surface axially slidable relativeto the drive mechanism; a first sensor associated with the first surfaceand a second sensor associated with the second surface, the sensorsbeing configured to measure a force; a computing device in communicationwith the force sensors, the computing device configured to compare thefirst sensor measured force with the second sensor measured force todetect a slip occurrence in one direction when the second sensormeasured force is not within a predetermined tolerance of the firstsensor measured force.
 11. The system of claim 10, wherein the activedrive device ceases movement of the elongate member in response todetecting the slip occurrence.
 12. The system of claim 11, wherein theactive drive device continues to drive the elongate member in responseto detecting the slip occurrence.
 13. The system of claim 12, whereinthe computing device is configured to: determine a drive forcerepresentative of the measured force of the first and second sensor inresponse to detecting the slip occurrence; compare the drive force witha slip threshold; and identify a slip condition in response to the driveforce exceeding the slip threshold.
 14. The system of claim 21, whereinthe computing device is configured to: receive the measured force of thefirst and second sensor to determine a drive force in response todetecting the slip occurrence; associate a slip tolerance and a slipthreshold with the drive force, wherein the slip tolerance is less thanthe slip threshold; compare the drive force with the slip threshold andthe slip tolerance; and determine a slip condition based on thecorrelation of the drive force relative to the slip threshold and sliptolerance.
 15. The system of claim 26, wherein the computing device isconfigured to: identify the first slip condition in response todetecting that the drive force exceeds the slip threshold; and identifythe second slip condition in response to detecting that the drive forceexceeds the slip tolerance but not the slip threshold.
 16. A slipdetection system on a drive system, comprising: a first surfaceconfigured to drive an elongate member in an axial direction, the firstsurface including a first sensor configured to detect a force; a secondsurface axially movable relative to the drive system, the second surfacehaving a second sensor configured to detect a force; and a computingdevice configured to: associate a threshold force with the secondsensor; monitor the measured force on the second sensor; and compare themeasured force of the second sensor with the threshold force to detectan initial slip occurrence between the active surface and the elongatemember in response to exceeding a predetermined tolerance of thethreshold force.
 17. The system of claim 16, wherein the computingdevice is configured to: detect a measured force of the first sensor inresponse to detecting the slip occurrence; and determine an activesurface slip threshold in response to the measured force.
 18. The systemof claim 17, wherein the computing device is configured to: associatethe active surface slip threshold with the passive surface to determinea passive surface slip threshold; determine a higher drive slipthreshold based on the sum of the passive surface slip threshold and theactive surface slip threshold; and output a drive force less than thehigher drive slip threshold to the active surface and passive surface toavoid slippage of the elongate member.
 19. The system of claim 18,wherein the computing device is configured to: determine a drive forcebased on the measured force of the first and second sensor in responseto detecting the initial slip occurrence; and compare the drive forcewith a slip threshold, and predict a slip condition in response to thedrive force exceeding the slip threshold.
 20. The system of claim 19,wherein the computing device is configured to compare the measured forceof the first sensor with the measured force of the second sensor todetermine a force difference, and detect a slip condition in response tothe force difference exceeding a predefined tolerance.